Luis Argerich - Astrophotography: Blog en-us (C) Luis Argerich - Astrophotography (Luis Argerich - Astrophotography) Thu, 12 Dec 2013 13:40:00 GMT Thu, 12 Dec 2013 13:40:00 GMT Luis Argerich - Astrophotography: Blog 120 90 Epecuen, an Incredible Story Epecuen at NightEpecuen at NightThe summer sky above the remains of the Epecuen Village in Argentina. The Pleiades, Orion and Canis Major dominate the sky from left to right.


Epecuen was (or is?) a small resort Village on the coast of the Epecuen lagoon in the province of Buenos Aires, Argentina. The place was flooded and totally destroyed in 1985, today the water is receding and the remains of the town can be seen once again. This is a short version of the incredible events that lead to the catastrophic destruction of the village. I'm grateful to the former citizens of Epecuen that told me their stories, it would be impossible to know the truth without their kind help.


Main Street IMain Street I


The village of Epecuen was settled on the margin of the homonymous lagoon in the early 20's. The lagoon is the last in a series of chained lagoons in the west of Buenos Aires. These lagoons present a natural occurrence of dry and wet cycles. Being Epecuen the last lagoon in the chain means that water can only leave the lagoon by evaporation. As a result the water is very salty, reaching 100 times the salinity of the sea and even saltier than the dead sea.


One of Many HotelsOne of Many HotelsThe Pleiades, Taurus, Orion and Sirius align over the remains of one of the many hotels that used to thrive in Epecuen.


The salinity and abundance of minerals popularized the village as a spa for thermal baths and to treat the symptoms of several diseases. Hotels and shops were build to attend a growing flow of tourism from nearby towns and later from the city of Buenos Aires itself. The village quickly became popular as a therapeutic resort and a vacation village reaching its golden age in the late 70's and early 80's.


Meteors at the BoardwalkMeteors at the BoardwalkTwo meteors and the small Magellan cloud above the boardwalk leading to the swimming pools.


In the 70's the chained Lagoons were in the middle of a dry cycle and the waters receded from Epecuen, work started to build channels and gates to drive water towards the lagoons both to fill the Epecuen Lagoon and also to irrigate the crop fields around the area. This was critical not only to the incipient tourist industry for Epecuen but also to the producers that worked the crop fields in the area.


The Swimming PoolsThe Swimming PoolsThe Magellan clouds and the bright star Achernar above what was once a swimming pool complex.


When a wet cycle started Epecuen reached a critical state as there were no plans to alleviate the level of water in the lagoon, this was in part a political decision as the crop fields generated most of the income of the local population of several bigger neighbor towns like Carhue. Sadly, the population of Epecuen was never alerted, they were never told about the impending disaster. Most of the citizens had no real plans and there were a few that just bought their lands or started a business in the town only months before the flooding.


The PortalThe PortalDamaged constructions of Epecuen and the Summer sky.


With the level of water already in a critical state due to heavy rains and winds a seiche finally overcome the defenses and the water entered Epecuen. Evacuation was started and there were no casualties but plenty of material losses. In just a few days the whole village was flooded and by 1996 there were 10 meters of water above the streets of the village. 


Main Street IIMain Street IIHouses and shops of Epecuen's Main Street with Jupiter shining above.


Hydraulic works were finally completed to provide both a way to flood or drain the system of lagoons as needed but it was too late for Epecuen. A dry cycle started and the waters receded leaving the remains of the town at ground level. Today people can walk around the streets of the village and contemplate the town after more than 25 years submerged in salty water. You can find plates, silverware, ads and objects in the ruins as everything had to be abandoned almost untouched during the evacuation. It's a ghost town that was, is and never will be.


Boulevard of Broken DreamsBoulevard of Broken DreamsOne of the village's boulevards near the coast of the Lagoon that finally flooded and destroyed the town completely.


At this time the water is coming back to its higher salinity level which is the host of a very special ecosystem that can only be found in a few places in the world because there are only a few species that thrive in such an extreme environment.

The village will never be reconstructed, wet cycles are needed for the crop fields that sustain the population of this area of Buenos Aires so the remains of Epecuen will flood and dry periodically in a rhythm dictated by both Nature and a series of gates and pumps that now control the water level.

These photos show the night sky above this place, unique as it can be. A collection of dreams and memories that lost a battle against Nature and politics at the same time. It was never a fair fight.



]]> (Luis Argerich - Astrophotography) Thu, 12 Dec 2013 13:39:46 GMT
The Occultation of Venus Occultation Sequence On September 8th 2013 the Moon occulted Venus for part of South America. After having missed the Venus transit in 2012 I thought it was a good compensation to live exactly in the area of the world where this occultation was visible. This "Syzygy" is one of the most visible occultations you can witness as it features the two brightest natural objects in the night sky.

The map shows the visibility of the occultation.

Sun, Moon and Venus The first photo shows the Sun still above the horizon looking carefully you will notice the Moon above and just above the Moon Venus. The photo, in some way, shows how Venus is actually easy to see at daytime if you know exactly where to look. A reference like the Moon is perfect, I could see both the Moon and Venus without any problems about one hour before sunset. I believe the same would have been possible at noon without much difference.

Moon and Venus before the occultation Once the Sun was below the horizon both the Moon and Venus became apparently brighter as there was more contrast between them and the sky. Venus was at magnitude -4.1 at this time so it was really bright next to the 3 days old waxing crescent Moon. There were some clouds but the conditions looked good for the occultation. 

Occultation at Dusk At about 6:50 pm Venus touched the Moon's dark limb and the occultation started. Visually the planet just disappeared from sight as it had just vanished in the sky. Dark limb occultations are quite magical, you don't see the occulting body so the eclipsed one just disappears from the sky in a few seconds.

The ISS visits the occultation While Venus was still behind the Moon the International Space Station made a pass crossing just next to the Moon. It was a very night sight. 

Half a Venus At 7:50pm almost exactly after one hour of the start Venus reappeared from behind the Moon's bright limb. I could take some photos of "half a Venus" as the planet was half occulted and half visible. 

Occultation and Earthshine As the planet got sepparation from the Moon I took a longer exposure to show Earthshine, the illumination that our own planet casts on the Moon's disc.

Emerging sequence The planet quickly got separation from the Moon. As the separation got larger Venus looked brighter. 

This occultation was a beautiful show, the Moon was in a very nice phase for photography and visual observing, it was quite high in the sky and the weather cooperated for the whole event. The next occultation from my location will be in January 2015, when the Moon occults Saturn,I'm sure it will be like this one only completely different!




]]> (Luis Argerich - Astrophotography) Venus conjunction moon occultation Wed, 11 Sep 2013 19:38:21 GMT
My Virgo Deep Field A Little Universe This is a very simple project that anyone can do with a DSLR a medium telephoto lens and a tracking mount. It shows an area of the sky between Virgo and Coma Berenices full of galaxies known as the Virgo/Coma supercluster. I was curious about what can be captured with a DSLR and in this case a 135mm lens and I was surprised at both the number of galaxies photographed and the level of detail that can be seen when zooming into the photo.

For this project I used my Canon 60Da DSLR with a 135mm lens and an Astrotrac portable mount. I took 1 minute exposures at F2.8 and ISO1600. I stacked about 60 of those exposures to reduce noise. I took the photos from a rural area, the cluster was low in the sky from my location so I had to take the photos quickly before it disappeared behind some trees. 

The next photo shows an annotated version of the photo, it won't be readable but the zillions of green labels will give you an idea of the number of galaxies that are in this area of the sky and can be captured with simple equipment.

Can you count the labels? Wow!

Here's a zoomable version:

And a zoomable version with labels:


After taking the shot I decided to do some crops and try to see at low resolution what can be seen about the most important galaxies in the photo.

The first crop shows the Markarian chain, a group of galaxies that from earth form a well defined and smooth chain. Some of the members in this group are related and move in the same direction at about the same speed but some others are just overimpossed by perspective. It's a remarkable group of big and bright galaxies and a very popular target for astrophotography.

This is M100 or NGC4321 a Grand-Design Spiral Galaxy that is almost face-on. I was surprised at the level of detail, this galaxy is 55 million light years away and we are using a wide angle lens but even then the spiral arms and the nucleous of the galaxy are clearly visible, even the faint outisde arms are visible in the image. A very surprising result and a beautiful galaxy.

Now an Spiral Galaxy but seen from its edge: NGC 4216 a metal rich galaxy. The halo of globurlar clusters around the galaxy center can be inferred from the photo. 

Now two interacting galaxies: NGC4435 and NGC4438 also known as "The Eyes", the galaxies are distorted by the gravitical interaction between them, it's surprising how this can be seen even at this scale.

This is NGC4654 an assimetric spiral galaxy, it can be seen clearly in the small scale crop that the arm on the left is more prominent.

Messier 91 is a barred spiral galaxy, the central bar can be seen as well as the two most important arms extending from the end of the central bar. To give a scale about brightness this is a magnitude 11 galaxy.

Another beautiful galaxy with a particular structure: M99. An unbarred spiral that has a normal looking arm and an extended arm that is less tightly wound. Can this be seen at this scale? Yes! The magic of pixels.

Messier 90 is a bright spiral galaxy. It has a peculiar satellite galaxi: IC3583 that can be seen at the top left of the galaxy as if they were two stars joined by a stream of light. So we got to a point where even small satellite galaxies are seen in a wide angle image. 

NGC 4567 and NGC4568: The Siamese Twins. Two galaxies that overlap in the sky and scientists believe are just begining to interact.

M60 and NGC4647. M60 is not a spiral but an elliptical galaxy the pair it forms with NGC4647 is known as Arp 116. Arp is a catalog of peculiar galaxies. This is the third brightest galaxy in the Virgo cluster and a giant galaxy that dominates its subcluster area.

Messier 88 an active spiral galaxy.

Finally M87, a giant elliptical galaxy one of the biggest galaxies near the Milky Way. It's an almost featureless ellipsoid and also one of the greatest sources of radio in the sky. A big monster!


This wide field shows detail that wasn't expected and we can go from a wide view of thousands of galaxies to details in the arms of spiral galaxies. I think this technique is also goot to monitor for supernovas as I think a bright supernova in one of the field galaxies would show up without any problems in the photo. A quick blinking between photos taken at different days can search for a supernova not in one but hundreads, even thousans of galaxies at the same time.

The resolution and detail can be enhanced augmenting the number of pixels in the image, this can be done using a longer focal length and making a mosaic. Mosaics are very common for high resolution astrophotography but even without a mosaic a good level of detail can be obtained.

Photographing galaxy clusters is fun and compared to other types of astrophotography the adqusition and processing are simpler, there are several clusters that can be photographed with modest equipment and the photos produced are not only beautiful but also informative and might be even useful to science in the event of a supernova.

Happy huntin!




]]> (Luis Argerich - Astrophotography) galaxies Sun, 28 Jul 2013 17:54:48 GMT
SuperMoon and SuperHalo Halo Bay

 June 2013 the Moon was full and near perigee almost at the same time, creating a new "supermoon". Supermoons are usually about 10-15% larger than regular full Moons and 20-30% brighter. That's not a powerful difference for naked eye observations but it does lead to some effects in photos. I went to photograph the supermoon to Punta Piedras a coastal area of Rio de La Plata, the widest river in the world. It was a cold night with temperatures around 3-4C and thin cirrus clouds in the sky. Soon after the Moon rose above the river a circular halo became visible. 

This is the halo at twilight, about one hour after sunset. It's not common to get pictures of halos when the sky is still blue from the sunset. It was barely visible to the naked eye and very clear in the photos. 

Halo and Reflection The halo is a common 22 degrees halo, it forms when the ice crystals in the atmosphere have a random orientation but in this case random is not so random as not every night produces a halo! Normally lunar halos are dim and colorless but this was really strong and the colors could be seen with the naked eye like a rainbow this is probably because the Moon was at perigee and close creating a halo as bright as it can ever be so I called it the super-halo.

There's a lot of excellentt information about halos at the website of my friend Les Cowley. One of the things I learned there is that inside the 22 degrees of the halo there's no refraction of light and that's why the sky looks darker inside the halo. That also explains why the reflection of the Moon on the water suddenly stops.

Infralateral Halo This photo shows how coolorful the halo was, red, orange and yellow were visible, if you look carefully you will also see a secondary colorful arch below the halo, that's a rare halo either an infralateral halo or part of a 46 degrees halo. 

Starry Night Halo The clouds were very thin and stars could be seen behind them, the constellation of Scorpius was almost complete inside the halo. This gives a good hint about how big the halo was, images were taken with a 14mm lens on a fullframe camera. 

Haloscape The halo lasted almost all night long, the contrast of the sky between inside and outside the halo was striking as well as its colors. It was a curious coincidence to find this optical phenomena on the same day as the supermoon and I think a few years will pass before I can write again about such a thing as superhalo.

]]> (Luis Argerich - Astrophotography) halo moon Sat, 29 Jun 2013 02:29:44 GMT
Comet C/2011 L4 Panstarrs from the South Hemisphere Comet Panstarrs March 2nd 2013 This comet was discovered back in 2011 at Hawaii by the Pan-STARRS telescope, an acronym meaning "Panoramic Survey Telescope and Rapid Response System" just a few hours after its discovery we knew a lot about this comet, we knew it was coming from outside the solar system from an hypothetical zone known as the "Oort Cloud", this was the first visit of this comet to the inner solar system and it was probably going to be visible to the naked eye in March 2013.  The Comet was named C/2011 L4 Pan-STARRS and I sincerely hope this is the last time a comet is named after an acronym. If our next forecasted comet c/2012 S1 becomes bright I expect it to be called "Nevski-Novichonok" and not "ISON". 

Comet Panstarrs and Iridium Flare Hunting Pan-STARRS was difficult because the comet was always very low in the sky. I started in February before sunrise and got to image the comet while it was still invisible to the naked eye. This is one of the first shots of the comet next to an Iridium flare.

Fan-Shaped Tail The comet was bright, and showed three main jet-streams in a fan-shaped tail. It was a nice view with binoculars or a telescope as the comet coma was very bright. In this photo Pan-STARRS is traveling the southern constellation of Indus. It was less bright than alpha-Indii a magnitude 3 star but close enough.

Panstarrs Panorama

This panorama shows the comet in the context of the surrounding stars near dawn in February 2013.

The Comet Appears The comet then moved to the evening and started to become brighter. On March 2nd 2013 it was already visible to the naked eye as a thin but bright object low in the western horizon. This wide view shows something similar to what I could see with my naked eye, the tail of the comet was surprisingly easy to see with the naked eye so it looked like a small hairline in the sky.

The First Great Comet of 2013 By March 5th Pan-STARRS was getting lower and brighter every day, it was now visible with the naked eye from light polluted places, I saw it from downtown Buenos Aires which is as light-polluted as any place can be. It looked lime a small eyelash in the sky. With binoculars the coma and the tail were very esy to see and very bright. It was already a nice show.

Comet Panstarrs March 5 2013 In the last reports the comet tail was becoming larger and broader so after perihelion the comet might become a very nice sight for North-Hemisphere observers. The comet is moving quickly to the North Hemisphere somewhere around March 7th or 8th it will become visible from lower latitudes north of the equator and it will move up so quickly that it will be next to the Andromeda galaxy on April.

Panstarrs Closeup This was certainly a very nice comet to observe and photograph it wasn't as big or as bright as comet Lovejoy in 2011 but it was without a doubt a nice show. I specially liked how people could see it with the naked eye and distiguish the comet nature as something different than a star. The comet is now moving to the North Hemisphere so I will be able to photograph it for just a few days, it was a very nice hunt and even if I really don't like its name I certainly liked its look.

You can check my gallery of photos of this comet here.


]]> (Luis Argerich - Astrophotography) comet panstarrs Fri, 08 Mar 2013 03:45:51 GMT
The First Comets of 2013 Comet Panstarrs and Iridium Flare 2013 might be remembered as "the year of the comets", we already have two comets near naked-eye visibility and comet ISON might become one of the brightest comets of the decade later in November. This small blog post is about the two first visitors we had: Comet C/2012 F6 Lemmon and Comet C/2011 L4 PANSTARRS.

Comet Lemmon Lemmon is the surprise of the year, it wasn't expected to be very bright but it suddenly started to brighten and is well ahead all the forecast and might reach magnitude 2 or 3 in March. It's a comet with a period of 11.000 years so it was here before but Earth was a very different planet back then. 

Not a Green Star I started to track Lemmon when the comet was crossing the Southern Cross (Crux) in January. It appeared as a green star in the middle of this small and easy to recognize constellation. But we know there are no green stars in the sky (sorry Zubenelschamali!). The green color comes from the ionization of diatomic carbon or from cyanogenic compunds that are quite common in comets. 

Lemmon at the SMC After a few days crossing southern skies towards the South Celestial pole Lemmon sprouted a long and thin tail, it passed nearby the Small Magellan Cloud and the globular cluster 47 Tucanae becoming circumpolar for southern hemisphere observers. 

Two Hours of Comet Lemmon in 10 Seconds The video shows how quickly comet Lemmon moves relative to background stars. The video was made from 120 shots of 1 minute each so it compresses two hours of comet wandering in ten seconds of video. Lemmon continues to brighten and is now moving northwards and will become visible to North Hemisphere observers in April. I hope it gets to naked eye visibility around march and it might be visible with the naked eye at the same time as our second comet: PANSTARRS.

Fan-Shaped Tail This is Comet C/2011 L4 PANSTARRS discovered in 2011 from Hawaii. Calculations back then showed the comet might become a naked eye object in March 2013 but comets are so impredictable, they can desintegrate, brighten enormously, dim suddenly, sprout a tail or even two tails. Nobody knows! 

Panstarrs Panorama PANSTARRS is a sungrazing comet with a very excentric orbit this means the comet is making its first visit to the Solar System, it will get close to the Sun and will probably not return. Since this is the first time the comet approaches our star anything is possible it can be a super-comet or a bust. It is now around magnitude 4 and as it approaches the Sun it will be visible very low in the sky after sunset and might be visible with the naked eye around March from both hemispheres. 

Panstarrs in the Morning Panstarrs has a fan-shaped tail and a very bright nucleus, recent photos show the tail in a yellowish color with some green color in the comet nucleus. As it continues to approach the Sun we can only continue to observe it and take photos and hope it becomes as nice as it can be.

With two comets already visible in the sky 2013 has started as a great year for comets and if ISON keeps to the expectations then it will be for sure the most dramatic year in decades for comet observers.

You can browse my ongoing gallery of Comet Lemmon here.

And the ongoing gallery for Comet Panstarrs here.



]]> (Luis Argerich - Astrophotography) comet Tue, 19 Feb 2013 16:41:02 GMT
The Occultation of Jupiter in January 2013 The year 2013 started with a very interesting astronomical event, an occultation of Jupiter by the waxing gibbous Moon. This events are quite rare as they are only visible in a small fraction of the world, this was visible from South America so I was very lucky as my home was just in the right place for the occultation path.

Daytime Conjunction I started taking photos at daytime, using the Moon as a reference Jupiter was visible to the naked eye even before sunset. Near opposition Jupiter is visible in daytime but is extremely hard to find it, you need a reference and the Moon was perfect, knowing where to look it was easy to spot.

A Mini Solar System I made a composite of two shots to show the Moon, Jupiter and it's satellites. Calisto and Io are very bright on the left side of Jupiter, Ganymede is on the right and Europa is so close to the planet that is lost in its glare. The star above-left Jupiter is w Taurus a main sequence "A" star. You can also see the dark limb of the Moon in this shot, that's where Jupiter is going to disappear. This shot looked to me like a miniature solar system so I liked it.

It's very difficult, impossible to get the Moon and Jupiter's satellites exposed in a single shot because the Moon is much more brighter and the dynamic ranges of cameras can't cope.Filters are of no help but there's a little trick if nature helps.

Jupiter in the Glare of the Moon Some clouds rolled in and with the Moon partially covered by clouds I could manage to get this in a single shot. The Moon craters are visible and the Moons of Jupiter are also in the photo. No tricks or composites needed!

Celestial Pair This wide angle shot shows how close Jupiter was to the Moon and how nice it looked to the naked eye, it was a very nice view with two of the three brightest objects of the night sky touching each other. (I hope I don't get porn-filtered because of 'touching each other')

Jupiter by the Moon And now we are ready for the occultation, Jupiter is very close to the Moon's invisible dark limb and suddenly it will start to disappear.

Now You See it Occultation about to begin

Occultation Begins The Moon takes a bite at Jupiter, this is an incredible view, Jupiter's equatorial bands are clearly visible but a quarter of the planet has just disappeared.

Half a Jupiter Midpoint in the occultation.

Crescent Jupiter This is a shot I liked because it shows Jupiter in a crescent shape, something that is impossible as Jupiter doesn't have phases but this is not a phase it's an occultation and while it seems that most of the planet has disappeared it is actually behind the Moon's dark limb.

Dark Limb Occultation This occultation was a fantastic event, the clouds were friendly and actually helped with the shots, I was able to see the occultation visually with the naked eye and the view through the telescope was amazing. It will take 13 years for this to happen again.


]]> (Luis Argerich - Astrophotography) conjunction jupiter moon occultation Tue, 22 Jan 2013 15:55:04 GMT
Airglow at Buenos Aires Airglow Show Airglow is a very curious atmospheric phenomena. It is produced by emission of light in the high atmosphere by chemical processes. The result is a display of blueish or green bands that move quickly on the night sky. Airglow needs a very dark sky without light pollution to be photographed. To the naked eye it is usually colorless because the human eyes are not very sensitive to its color.

Airglow at Orion On December 12th 2012 there was a strong and unusual display of airglow near Buenos Aires, Argentina. I was in a rural location planning to shoot the Geminid meteor shower and was taken by surprise by this event. The bands could be seen weakly with the naked eye as if they were very thin clouds but in the photos a strong green color revealed its nature as airglow. This shouldn't be confused with the Aurora, from my location Auroras are never visible but airglow can be seen all over the world.

Airglow Timelapse This video shows how the airglow patterns changed quickly at the North side of the sky. The pleiades are visible just on the left of Jupiter (very bright) with Orion on the right. The patterns danced for about 15-20 minutes and then suddenly disappeared. You will also see several planes and even some fireflies!

Magellan Clouds and Airglow I The display was even stronger to the South where the green bands contrasted strongly against the sky. The Magellan clouds can be seen here with the Large Magellan Cloud in the center of the frame. The Small Magellan Cloud is near the top of the frame with the globular cluster 47 Tucanae just next to it. It does look like the Aurora but it's not.

Airglow Planet This stereographic projection shows the sky wrapped around a 360 degrees view of the location. The airglow bands can be seen clearly. These bands are paralell to each other but seem to converge because of perspective. The same that you can see with train tracks.

Airglow Patterns There are some reports about airglow increasing in the last months but it's not clear is this is because some natural cause or just because more and more people are shooting the night sky with better cameras. This case was particular because it was very strong, colored and near a very big city like Buenos Aires. I've photographed airglow before but only in very remote locations with very dark skies and no light pollution, it was my idea that photographing or seeing airglow in less than perfect conditions was impossible but I was wrong.

You can check the photos at this gallery.

]]> (Luis Argerich - Astrophotography) Nightscapes airglow Fri, 21 Dec 2012 17:52:58 GMT
Three planets, the Moon and more on December 2012 On December 2012 three planets: Saturn, Venus and Mercury were found aligned over the Eastern horizon before Sunrise. The conjunction took different configurations and was joined by the Waning Crescent Moon on December 10th and 11th. The thin Moon and the three planets displayed a beautiful show that was easy to see with the naked eye from all around the world. My views from the South Hemisphere will surely look upside-down or mirrored to observers in the North side of the globe.

With the night just ending and the horizon starting to glow by the sunrise two planets were already visible: Saturn and Venus. Since the sky was still dark enough several stars could be seen including Spica and Zubenelgenubi, those bright stars are very near the ecliptic so they can be occulted by the Moon and rarely by planets. Zubenelgenubi will be occulted by Mercury in 2052(!).


In this shot you can also see the bright stars Alpha and Beta Centauri and looking carefully the bright globular cluster is also visible, it's visible to the naked eye and even in a wide angle photo as this one with the sky not fully dark it appears as a diffuse blob, it's really magnificent.

Earthshine is visible in this photo. The bright side of the Moon is lit by the Sun and the dark part is lit by light reflected from Earth, hence the name "earthshine". In this photo you can also see clearly that Zubenelgenubi is a double star, the brightest star in Libra. Venus is just raising and looks very bright while Saturn is at the top of the frame. Zooming in a lot and eluding a couple of stars I was able to find Titan, Saturn's brightest satellite, in this photo. At magnitude 9 it's just visible below the planet, but you have to zoom a lot. 

This is from December 9th before the Moon joined the conjunction you can see Spica, Saturn, Venus, Zubenelgenubi and Mercury aligned over the ecliptic. Venus is displaying an oval aureole, a curious atmospheric phenomena that is not very common. Mercury was really difficult to see due to thin clouds, almost impossible with the naked eye but ok with binoculars.

Without clouds and with excellent transparency Mercury was easy to see with the naked eye, you will find it without problems in this photo. There's a thin window of time to catch mercury, it has to be a few degrees above the horizon to overcome atmospheric extiction but before the sky turns too bright to wash it. December is not the best month to observe Mercury from the south hemisphere because the nights are very short as we are in the Summer but the observation of Mercury actually favors the south hemisphere. In May, for example, you can see Mercury in the full darkness of the night.

The conjunction above Rio de La Plata with the city of Buenos aires on the right. This is almost exactly how the show looked to the casual observer, the Moon and Venus were very bright and Mercury was an easy naked eye catch but only if you looked for it. The blue color in the river and the glow of sunrise at the horizon made the event a very nice sight for those that were awake.

You can see more photos from this conjunction at this gallery.

]]> (Luis Argerich - Astrophotography) Venus conjunction moon Wed, 12 Dec 2012 18:08:32 GMT
High Resolution Lunar Images with a DSLR Gibbous Imaging the Moon in high resolution is quite a challenge, at high magnifications the most difficult problem is to fight atmospheric turbulence, what the astrophotographers know as "seeing". The turbulence blurs the photos randomly and there can be quite a huge difference in detail between two photos taken just seconds apart. 

To fight turbulence astrophotographers use a technique known as "lucky imaging" you take hundreads even thousands of photos and then using ad-hoc software you select the sharpest frames from your captures. This is usually done in video mode to capture more frames per second. Now that DSLRs have video modes of good quality we can use them as planetary cameras capturing videos and processing them to create high resolution images of the Sun, Moon and planets.

This is an example of how a video looks using the 640x480 crop mode of a Canon T2i at 60 fps

You can see the effect of atmospheric turbulence in the images, some of them are quite sharp and some of them are very blurry due to turbulence. You can also use these videos to check how the "seeing" is for the night, the steadier the image looks the better the results will be. In nights with bad seeing you need to take many frames as most of them will be blurry. In general terms for the Moon I use videos from 30 seconds to 2 minutes.

If you plan to do a mosaic you need to take many videos making sure you don't forget to cover any part of the Moon, I usually allow a 25-30% overlap between photos. Remember that without perfect tracking the borders of the images won't be useful.

For the "Lucky Imaging" part I use Autostakkert2! a great and free software that automatically aligns and stacks the best frames of a video. I choose the best 500-600 frames to be stacked. Before running Autostakkert you need to convert the videos to a format that AS! will recognize. I use a free utility called "super" to convert the .mov files from my Canon DSLR to .avi with a RAWloseless codec (to maximize quality).

This is the result of one of the stacked images. Once stacked I process the resulting .tiff files with Registax6 applying wavelets to sharpen the images, it's amazing how the detail just pops when you apply wavelets to a stacked image. 

Once all the panels have been sharpened I finally use Hugin to create the final mosaic.

Lights and Shadows at the Moon The result has plenty of detail and depending on the telescope you use for the images it will look as good as the mosaics created with a dedicated planetary camera.

If you have a lot of time you can also add a barlow lens and then take many more videos for a higher resolution final image.


Example for the complete Moon Mosaic:

- 1500mm telecope (Mak-Cass 5'')

- 2x barlow lens

- Canon T2i in 640x480 @60fps mode

- 180 videos 1 minute each

- Stacked with Autostakkert2!

- Sharpened using Registax6

- Mosaic assembled with Hugin


And this is the final result:

On the Way to the Full Moon Making lunar Mosaics from DSLR videos is a time-consuming activity but it is also a lot of fun and the results look great, if you own a telescope and a DSLR it's something that you can do in those nights when the Moon is too bright for astrophotography.


]]> (Luis Argerich - Astrophotography) moon Mon, 29 Oct 2012 19:03:37 GMT
The Quadruple Conjunction on August 21 2012 Quadruple Conjunction at Dusk During the month of August two planets: Mars and Saturn passed near the bright star Spica (alpha Virginis), the conjunction took several different triangular shapes. Triangles are powerful shapes for the human brain and being the 3 objects of similar apparent magnitude the view, to the naked eye, was really captivating. On August 21th the waxing crescent moon joined the show to make the conjunction a quadruple. Since the conjunction was on the West I could take a photo a few minutes after sunset while the low clouds were still lit by the sun below the horizon. Here's an annotated version.

Now let's move a few days back to see how the conjunction looked without the Moon.

Spica, Mars and Saturn This photo is from August 14th, Spica is on the left, Mars at the center and Saturn on the right. I used a fog filter combined with a star filter to bloat the stars and keep their real colors. Spica shines in a bright blue at magnitude 0.95, Mars is orange/yellow at Mag 1.3 and Saturn is white/yellow at magnitude 1. The separation was 1.5 degrees from Spica to Mars and 2.5 degrees from Mars to Saturn. Seeing three bright celestial bodies of contrasting colors in a tight are of the sky inmediately draws our eyes to the sky, this was a conjunction that most people noticed not only astronomers.

Back to August 21st I took a portrait of the conjunction. Without the fog filter the stars get saturated quickly so the real  colors are lost. The photo shows how close the Moon was to Spica from my location, about half a degree of separation. To the naked eye they were almost touching.

Candlelights In this photo I tried to show how powerful the triangle shape looks to the human eyes. Even above the bright lights of the pier the conjunction stands out as a bright display. The Moon is a welcomed visitor just next to the triangle above the western horizon.

Conjunction Sequence The photo is a sequence of stacked shots showing how the conjunction drifter in the sky setting on the west. The Moon looks different in each frame due to some passing clouds. It's interesting to see how Spica and Mars shared the same celestial highway as they are displayed in very similar positions next to the Moon while Saturn was setting on the right side.

Conjunction at Moonset The last photo I took shows the Moon setting covered by clouds with Mars and Saturn barely visible behind the cloud cover. The Milky Way can be seen above the conjunction starting it's movement down in the sky. 

Quadruple conjunctions between bright objects are always very interesting and this time the triangle shape and contrasting colors were a very nice bonus.

Youu can check more images I took from this conjunction at this gallery.


]]> (Luis Argerich - Astrophotography) Nightscapes conjunction Thu, 23 Aug 2012 18:04:03 GMT
The Conjunction on July 15th 2012 The Bright Square of July During June and July 2012 we could see a series of beautiful conjunctions between Venus, Jupiter and Aldebaran. July's 15th was the big show for the event as the Moon was going to join the conjunction. It was freezing cold and cloudy at my location but still we were able to get some photos of this nice celestial event.

Pleiades, Hyades and Conjunction The conjunction rose above the water of Rio de La Plata while the night was still dark. It's the middle of the winter in the south hemisphere and the nights are long and cold. Jupiter was the first to rise followed by the Moon and Venus. After a few minutes a beautiful "square" formed in the sky, just next to the pleiades cluster. You can see the pleiades on the left of this photo.

Conjunction with Orion and Sirius The Wide angle view shows how tight the conjunction was in the sky. Just to the next of the conjunction you will recognize Orion, maybe upside-down because I live in the South Hemisphere and just a palm to the right of Orion is Sirius, the brightest star in the Night Sky. You can see that Sirius is brighter than Aldebaran but Venus and Jupiter are much much brighter and the Moon tops them all. The clouds were not a problem they just created a natural difussion effect on the planets and stars. 

Dawn of the Conjunction A few minutes before sunrise the conjunction was still easy to see with the naked eye. The clouds started to turn red and orange illuminated by the Sun still a few degrees below the horizon. The horns of the bull, Taurus are easy to see in this photo. 

Conjunction Panorama at Dawn A wide panorama just before sunrise. The brightest area of the horizon where a big boat is seen marks the point where the Sun is just about to rise. Sirius is still clearly visible at the right of the panorama ans can be compared to the brightness of the conjunction. With the sky turning in colors the conjunction looked even better. Sometimes clouds are friendly after all!

You can check my gallery for this conjunction here:

2012 is a nice year for conjunctions and occultations, it was a good thing to be able to see and photograph this event even with some clouds.

]]> (Luis Argerich - Astrophotography) Venus conjunction moon Tue, 17 Jul 2012 16:57:54 GMT
The Eta Carina Nebula A Dark Nebula and a Bright Nebula

The Eta-Carina nebula is one of the nicest things you can see in the sky from the South Hemisphere as long as you have access to dark skies. I decided to create a special gallery in my website to collect the different nightscapes that feature this nebula in a leading role and this post is a quick description of what the nebula is and how it looks from my location.

Nebula and Clouds

The nebula is around the world-famous star Eta Carinae, a stellar system located at abour 7500 light years from Earth. One of the members of the Eta-Carina system is a massive blue luminous star about 120 to 150 solar masses. The star is so massive that is close to the Eddington limit meaning that its gravity is barely enough to contain the heat and radiation that the star generates. 

Scientists agree that Eta-Carina will one day explode in a cataclismic event and become a supernova or even an hypernova, the event will be without a doubt the biggest explosion in the history of our galaxy. The star will become so bright that it will be possible to see it in daylight and it will cast shadows and be bright enough to read a book by its light at night. This can happen in a million years or it can happen tomorrow, nobody knows.

Carina and the Tower Eta Carina is a variable and erratic star. Today it's a magnitude 4 star, barely visible to the naked eye. In 1843 the star experienced a small explosion and became the second brightest star in the sky at magnitude -0.8, only Sirius was brighter. The event ejected a lot of material and is now part of what we know as the Eta Carina Nebula.

The Nebula is very bright and from a dark location can be seen with the naked eye. It lies just in the middle of the Milky Way in a very photogenic area of the night sky. It's near the coalsack nebula, a very dark patch of dust that occults the Milky Way. These two nebulas create a beautiful contrast in photos. The coalsack nebula being so dark and the Eta Carina nebula being so bright.

This poster shows some of the many deep sky objects that can be found around the Eta Carine Nebula and the nebula itself. With a higher magnification the center of the nebula features two expanding lobes from its recent ejection of material creating what is known as the "Homunculus Nebula"

Eta Carina Above the Trees Eta Carina is a fascinating star for astronomers, photographers and admirers of the night sky, it keeps ticking and ticking above our heads waiting for its final cataclismic show. 

I will keep shooting the nebula and adding photos to the gallery and maybe one day I will be one of many bloggers writing about the mother of all astronomical events. You never know...

]]> (Luis Argerich - Astrophotography) Nightscapes Fri, 06 Jul 2012 20:54:32 GMT
Asteroid Hunting Conjunctions near Dawn [APOD]

I usually don't photograph asteroids and I've never hunted for asteroids before. In Nightscape photography it's quite difficult to find a way to show an asteroid in a beautiful context. They are just too dim. I missed a chance when Vesta was really bright and easy to see with the naked eye a few years ago due to weather and I thought that was all between me an asteroids.

But while photographing the cojunction between Jupiter, Venus and Aldebaran I found, with surprise, that asteroids Ceres and Vesta were both in the same field of view as the conjunction. At magnitudes 7.85 (Vesta) and 8.6 (Ceres) they were not visible to the naked eye but should be easy to capture them with the camera. I know I can get up to magnitude 11 or even more with a long exposure and my cameras so the hunting begun.

In my first try it was easy to capture Ceres as it was near Jupiter but my field of view was not large enough for Vesta. I used stellarium to see where Vesta was supossed to be and determine which bright stars should be included in the frame to capture both asteroids. I found the star f-Tau a magnitude 4 star was just above Vesta so including f-Tau should also include Vesta. Another early wake up and another try.

After taking the photos I used stellarium again to recognize the star-field and find the Asteroids. Vesta was a very easy find located below f-tau as expected. Ceres was dimmer but appeared clear in the photo too. Now it was 2 out of 2. I got Jupiter, Venus, Ceres and Vesta in the same photo along with the Pleaiades, Hyades and Aldebaran. If you like conjunctions as I do you will realize this was fun.

I kept shooting until sunrise and I was very surprised to find that the asteroids were still visible in the photos in the glae of dawn. The horizon was very bright and they sky turned a definitive blue but yet the brightest stars were visible to the naked eye and the two dim asteroids were also visible in the photo. This is the first time I've seen asteroids in a scene that is not taken at night time. 

If you want to get Ceres and Vesta use Stellarium to find references near them to help you frame the shot. Use a 50mm or higher focal lens as the longer the focal length the more light you will be able to capture shoot as long as you can avoiding trails at the widest aperture you can use to avoid comma in the borders. Pump the ISO as needed, usually up to 1600.

I'll keep shooting this conjunction waiting for the Moon to join the show on July 14th and 15th. Both Ceres and Vesta will still be in the field of view, now that will be quite a grouping!

]]> (Luis Argerich - Astrophotography) Venus asteroids conjunction Sat, 30 Jun 2012 19:18:49 GMT
Partial Lunar Eclipse on June4th 2012 Partial Eclipse Sequence This eclipse was just one day before the transit of Venus so it didn't get a lot of attention. It was also just a partial eclipse, not a total one with about 28% of the Moon being obscured.

For this eclipse I traveled to the city of Chascomus, as the eclipse was near moonset from my location I needed a clear west horizon and Chascomus has a very nice natural lagoon with a clean horizon towards the West. Sunsets are very beautiful at this place.

I arrived at 6am with temperature in -3C, the weather was almost clear with some friendly looking passing clouds. The penumbral part of the eclipse was starting at 7pm but the umbral part was already starting so I took some photos.

Umbra Stage This photo shows the Moon inside the Umbra of Earth, usually this part of the eclipse is not really noticeable to the naked eye but this time, I don't know why, the darkening on the top of the Moon was evident. Maybe because of the very clear thin air or the weather conditions. I'm not sure. 

When the penumbral eclipse started it was really easy to see the moon darkening, a very nice show and the Moon was still quite high in a dark sky. Due to the excellent visibility as low as 0 degrees at the location I was prepared to shoot the whole eclipse. As the moon was darkening I took several photos producing the sequence that starts this post.

Maximum Eclipse This photo shows the maximum phase of the eclipse, the shadow of the Earth is taking a good bite on the Moon. At this point some clouds started to appear coming from the South, that's usually a bad sign so I switched to a wider focal length to try to capture some nightscapes of the eclipse. 

Eclipse at the Lagoon Here you can see the Lagoon and the partially eclipsed Moon above. The "bite" on the moon is clear and was easy to see with the naked eye. There's a thin layer of fog above the lagoon surface that you can see in the photo. The reflection of the Moon was a beautiful sight and the light of the Moon lit the clouds too. As the Moon was getting lower it will soon disappear into the thick clouds so I was both lucky and happy to be able to take this shot.

Eclipse Up & Down Now you see the partially eclipsed Moon (top) being also eclipsed by clouds (bottom), a few seconds after this shot everything was over as the clouds swallowed the Moon. I couldn't take photos of the Moon setting eclipsed as I expected but at least my memory card was not empty. The next lunar eclipse from my location will be in 2014, a long wait!




]]> (Luis Argerich - Astrophotography) Nightscapes eclipse moon Sat, 09 Jun 2012 13:25:56 GMT
The May 2012 Supermoon SuperMoon 2012 On May 6th 2012 at 3:34 am the Moon was full; two minutes later the moon was at perigee, its closest point in its orbit around earth. The result was a full moon slightly bigger and brighter than the average fullmoon. This was widely circulated as a "supermoon", the difference in size and brightness is not really that super but if it helps to get people interested in astronomy and the moon then it works for me. In this post I will show some of the photos I took for this event.

SuperMoon Conjunction On May 4th one day before the event there was a nice conjunction between the Moon, Spica and Saturn. Spica is a mag 1 star and Saturn was at similar brightness. I had a fight against some clouds to take the photo, an early warning of what was coming next.

Colorful Supermoon The Night of the "event" was quite cloudy, but the moon is so bright that it can make thin clouds translucid and display a colorful corona around it. I combined 9 different exposures to produce this HDR photo of the supermoon among the clouds.

May 2012 Supermoon in Color When the sky finally cleared I was able to take some portaits of the supermoon without clouds. I stacked several photos and increased saturation to show the colors on the Moon surface. The full moon is usually a difficult target for photos because it has no shadows so it looks very flat. Increasing color is one of the ways to fight against that flatness.

And the next day I went to the coast of the river to photograph moonrise, the clouds were again a problem.

The Color of Moonrise Because of the clouds it was impossible to take a shot at the moon just rising, but once it reached some height it was bright enough to be seen behind the clouds. It looked really big.

The Stars Against all Odds With the moon slightly higher I took this shot and I was really surprised by the result. Even with a fullmoon and clouds several stars could be seen in the photo. Above the Moon you can find Zubenelgenubi (alpha Librae) a star that has a reputation for looking greenish and it certainly looked green this time! A little above Zub you will find a nice string of stars like pearls that are part of the constellation Hydra, that's a nice asterism. Several other stars can be see zooming in. Quite a curiosity!

Supermoon and Corona With the moon even higher I witnessed a beautiful scene: The Moon displayed a colorful Corona around it and casted a bright reflection over the river. Trying to show what I could see in a photo was nearly impossible. I had to take three different exposures and combine them to get a result that looked similar to what my eyes could see. I think this shows how well human eyes adapt to different levels of brightness, it was so easy to see "everything" with the naked eye and it was so difficult for the camera to reproduce it.

This year's "supermoon" was a nice show many people got interested and went to different places to see moonrise or the moon itself and hundreads of viewers took their first photos of our natural satellite. At the end I even liked the clouds, we are friends again.


]]> (Luis Argerich - Astrophotography) Nightscapes moon Tue, 08 May 2012 17:45:43 GMT
The Processing and Over Processing of Night Sky Images I will start this small article with my premise:

“If you over-process a night sky image to the point of destruction it will have better results for the general public”

To make my point more clear I will show what I mean with a couple of images. I will start with this photo I took of the Winter Milky Way from the South Hemisphere:

This is a photo I like. It was taken from a very dark location away from light pollution and shows the beauty of the Milky Way from Carina to Scorpius. Dark nebulas as the pipe nebula in Scorpius or the Coalsack nebula in Crux are clearly visible. Other nebulas as the Lagoon (M8) and Triffid can also be identified. The image shows the Milky Way brighter than what can be seen with our eyes because the camera is more sensitive to light but there’s not a huge difference.  For an observer that was in that place this photo will be a good representation of what he saw and felt at that moment.

Now let’s apply a lot of contrast, saturation and sharpening to that very same image. The result is this:

In astronomical and photographical terms the photo is now destroyed. The sky is never pitch black as the photo shows it, the Milky way is never that bright, the fine details are gone and everything is now reduced to a bright blob of light against a very dark sky. It sounds terrible and it is terrible but believe me that the general public will prefer this overdone image to the original. And I also think I didn’t overdo the image enough, more damage can be done and more “spectacular” the photo will be.

I’m not going to do the experiment of uploading both photos to photo-sharing communities because I don’t like to use my viewers as Guinea Pigs but I’m totally convinced that the overprocessed image would win the battle by a huge margin.

So why is this happening? I think it is because the public, without a knowledge of astronomy, is likely to believe in almost any image of the night sky you present as something real. They have not enough knowledge of the sky or astronomy to say the photo was totally overdone.

If you present a photo of a green cow the general public will reject it saying things as “I like the photo but not the processing”, “This is not real”, “overdone”, “photoshopped” and if they have a bad day you can get something as “this is not photography”. Been there, done that.

This happens because everybody knows cows are not green, so when they see a green cow they know the image has been manipulated and they feel the photographer tried to fool them, the result is a rejection towards the photo. If you do the same with a night sky image presenting a bright green Milky Way arching above the hills of a landscape the public will love it. They just don’t know the Milky way can’t be that bright, they just don’t know it is not green and they just don’t know what astronomical features were destroyed in the processing. So without a reason to think the photo is overdone they will just admire what they see and love the photo. The comments will be “stunning”, “I never thought the sky could be so beautiful”, “your location has some amazing skies” and so on.

Even photographers will think the photo is great because they can’t tell the degree of processing applied if they don’t know hoq the real thing is. When photographers without any familiarity with the night sky start their journey in astrophotography or night landscapes they tend to overprocess the images too. This is easy to explain as they try to produce with the photos the result they will like as vieweres.

So what happens if you are a photographer with a knowledge of astronomy? Do you try to keep your photos honest and real but with your artistic touch or do you just overprocess the photo to the point of destruction to impress the public? To be honest I have no idea of the answer to this question.

As an example Iwas asked to present some photos for an exhibit recently and I had to decide between honest photos with a low impact to the public or destroyed photos to generate some “wows” I went with the first option because I need to like my photos too but from a sales, marketing or visibility point of view that’s certainly the wrong decision.

This is a view of the Milky Way above a lake in Patagonia. I took the artistic license to make the sky a little more blue than what it really was but there’s not a huge difference from the real thing. The Magellan clouds are visible on the left and they have the brightness that matches what you would see from such a dark location. There are even some traces of airglow near the horizon, that’s the brightness of earth’s atmosphere and it can only be seen in very dark places without light pollution. You can see them as bands or streaks in a greenish color. I was there and the photo represents what I saw, and what I liked in a good way.

It’s interesting in astronomical terms and I hope it’s also a beautiful view of the night sky, but can I do it better? worst?

When I show this overdone version people say “wow” they point how bright the Milky Way and the Magellan Clouds are, they ask about the location, and viewers with good eyes signal there’s a hint of “aurora” at the horizon. I can either be happy with that or just embarrassed because nothing they say is real and the photo has been destroyed. The big Magellan cloud looks like a light tube up there, I feel terrible to even show this as an exercise but print this photo big in metal paper and you have a winner. You will see people gathered around the photo, you will see photographers that want to take a workshop with you and there’s a chance you can even win some contests with such a photo, it’s novelty, it’s unique, it’s bright, it’s destroyed.

If an astronomer sees the photo, professional or amateur he will be  disgusted. But how many astronomers do you see around you now? As I say “you can’t argue with success”.

If you browse online you will find plenty of images of the Milky Way and other night sky features described as “stunning” when they are actually overprocessed shots to the point of destruction. The question is how many viewers notice that and if that is or not important to the photographer. In most cases the photographer is honest with his own processing, he just doesn’t know he is destroying the sky in the photo, he processes until he likes it. Honest photo, honest viewers, but nothing is real.

This is something that I have been thinking in the last weeks and I think it can create an interesting debate about what is the right way to go. It’s a terrible Dr Jekill and Mr Hyde feeling, I know I can make my photos more succesful if I just make them more horrible to me.

Maybe this is in some way similar to what happens with HDR. The general public loves HDRs, they are bold, bright and they look very real but many photographers don’t because they know the image is overdone to a point they don’t like it any more. So what do you do? Do you process to your likes or do you process to be succesful? Believe me you don’t want to feel that way.

If you ask me I prefer to avoid the wow factor and I hope the viewer can get interested in the night sky and learn how many beautiful things can be seen out there, the importance to fight against light pollution and that if the photo is honest there’s probably a lot to learn from it and that it can be beautiful too. If I get a “wow” from a photo that I know is not overdone then I will feel really good, the only problem is for that to happen I need to go thru many many low impact photos when I could just do a little overprocessing. The debate is now open.

]]> (Luis Argerich - Astrophotography) Nightscapes Mon, 30 Apr 2012 17:46:59 GMT
Strange Conjunctions: Mercury, the Moon and Uranus An astronomical conjunction is a visual encounter between two or more celestial bodies as seen from some location on Earth. Conjunctions between the Moon and some stars or a planet are very common. Conjunctions of two ore more planets are also common. Some conjunctions are particulary bright like the Venus - Jupiter encounter on March 2012. On the other hand some conjunctions are quite rare or strange, this is about one of the rarest conjunctions I've photographed.

The Moon, Mercury and Uranus Annotated On April 18th 2012 just before dawn the Moon, Uranus and Mercury were in the same area of the sky. Both Mercury and Uranus are difficult planets for visual observation making this a very strange event. Mercury is always close to the Sun, the planet makes a few apparitions at dawn or dusk every year, from my location at the south hemisphere mercury rose above the East horizon at 5am and was visible until 7am a few minutes before sunrise. Uranus is barely visible with the naked eye but when you have a reference like the Moon and Mercury here it is doable. Making the conjunction better the Moon was a thin waning crescent displaying a nice earthshine. This annotated photo also shows Tx Psc, a very strange star, more on that in a few paragraphs.

The Moon and Mercury Over Buenos Aires Mercury and the Moon high in the sky before sunrise. Uranus was no longer visible to the naked eye. This photo shows how high Mercury can be seen from the South Hemisphere at the right time of the year. Almost 20 degrees high with the Sun yet below the horizon. Mercury was at maximum elongation exactly on this day.

The Circlet and the Carbon Star This photo shows the Moon and Mercury on the right. The Moon was in the middle of the asterism called "the circlet" in Pisces. If you look at the large version of the photo you will notice a small red dot just below the moon. That's not a bad pixel! It's 19 Psc or Tx Psc, a Carbon Star. Carbon stars are the reddest stars in the night sky, they are dim and difficult to see but this time the moon was a wonderful reference.

Conjunction and Circlet The circlet asterism is clearly visible here and Mercury is to the right. Uranus should still be visible but really small in this photo. The glow on the horizon was more intense from the impending sunrise. 

Mercury - Moon Conjunction The Moon is still nice and clear, mercury barely visible and sunrise is just about to happen.

From all the conjunctions that can be seen with the naked eye I think that a Mercury - Uranus pairing is probably the strangest of all. Adding the moon just in the middle of the circlet and close to a Carbon star was a very nice bonus. I'll keep looking for this strange events.

You can browse all the photos from this conjunction here:

]]> (Luis Argerich - Astrophotography) Nightscapes conjunction Mon, 23 Apr 2012 18:44:58 GMT
Conjunctions of Venus, Jupiter and the Moon in 2012 Conjunction at the Pleiades

In the first months of 2012, Venus and Jupiter started a chase, the planets were closer and closer each day until their maximum approach on March 13,2012. This produced several interesting conjunctions. In the first photo Jupiter is at the left, then the Moon between the trees and Venus is higher on the right. The Pleiades cluster M45 is on the right side of the photo. The whole view was fantastic.

Mercury, Venus and Jupiter Mercury joined the conjunction briefly on February, Mercury is not an easy catch as it is frequently too close to the Sun to be seen, on this evening Mercury was bright and visible just after sunset producing a straight line with Venus and Jupiter.

Three Degrees of Separation On March 13 Venus and Jupiter were separated by only 3 degrees hight in the sky after Sunset. A beautiful sight that was only going to get even better.

Venus, Jupiter and the Moon On March 25th the thin crescent Moon joined the conjunction, then the three brightest natural objects in the night sky were visible in a small region of the sky. The view was really fantastic and the Earthshine of the moon made the scene really special. This was very nice but the display wasn't over yet.

Conjunction and Earthshine The next day: March 26th the Moon was separated only one degree from Venus, the thin Moon and the very bright Venus were a really beautiful view in the sky, almost magnetic. 


The Moon and Venus at Daytime And this is how it looked in the middle of the day. Finding venus was very easy as the moon helped as a reference. In the photo Venus can be seen in phase near 50%.

The conjunctions were beautiful but this is not over yet as Venus is slowly traveling towards the Pleiades (M45) this visit happens every 8 years when Venus reaches its northernmost declination. This year the Visit will take Venus just next to the Pleiades almost touching several of the cluster stars, this will probably be my next blog post!

]]> (Luis Argerich - Astrophotography) Nightscapes Venus conjunction Wed, 28 Mar 2012 06:42:40 GMT
The Opposition of Mars in 2012 The 2012 Opposition of Mars Mars reached opposition on March 3, 2012. The Sun, the Earth and Mars lined up in a straight line bringing Mars closer to earth on the 5th. Oppositions of Mars occur every 2 years so this is the brightest we'll see Mars until 2014.

Since the orbit of Mars is not perfectly symmetrical not all the oppositions are the same. This event was very unfavourable as Mars was far from the Sun, future oppositions will get better and better until a fantastic show in 2018 bringing Mars just as close as in the great opposition of 2003. How many times can I write "opposition" in a single paragraph?

Opposition in Leo In 2012 Mars was at Leo near Regulus for the opposition, Denebola was also visible but the area doesn't have many bright stars and that made the red planet stand out. The color of Mars can be affected by dust storms and this time it was bright red. I took a portrait photo using a telescope to register this opposition it will be nice to compare the apparent size of the planet against the 2014 opposition.

2012 Opposition Portrait There's some detail on the surface and the polar cap is easy to see even with a small telescope (5''). Some orographic clouds above Mons Olympus are visible towards the left side of the planet. 

This is not the end of the Mars Season yet, from the South Hemisphere the Moon will occult the red planet on September 19th. That will be a gorgeous event to see and photograph as the red of Mars will contrast very nicely against the Moon. 

]]> (Luis Argerich - Astrophotography) Nightscapes mars Wed, 07 Mar 2012 16:49:35 GMT