RBA & AF Astrophotography

Orion, from Head to Toes

Posted: October 22nd, 2010



From the APOD: Cradled in cosmic dust andglowing hydrogen, stellar nurseries in Orion the Hunter lie at the edgeof a giant molecular cloud some 1,500 light-years away. Spanning nearly 25 degrees, this breath-taking vista stretches across the well-known constellation from head to toe (left to right). The Great Orion Nebula, the closest large star forming region, is right of center. To its left are the Horsehead Nebula, M78, and Orion's belt stars.  In this 3x8 mosaic of broadband telescopic images, additional image data acquired with a narrow hydrogen alpha filter was used to bring out the pervasive tendrils of energized atomic hydrogen gas and the arc of the giant Barnard's Loop.

Personal notes about the image to be added shortly...



Iris Nebula Wide Field

Posted: October 8th, 2010



Click here for a larger version

Sometimes, when you're at it processing an image with certain goals in mind, in order to solve a particular problem, you make the wrong decision or take the wrong step. Often, the smart thing to do is to back off and try again. Some other times, you move forward and "hammer" the image again and again, as if one bad processing decision could be fixed by another one. This may work sometimes, but if you're not careful, you end up overcooking your image.

This is one of such images :-)

Captured last October at Lake San Antonio (California) during the first couple of darkness hours over 4 the nights I spent camping there during Calstar, it's a 2x2 mosaic of the area around the Iris nebula in Cepheus. The biggest challenge here wasn't so much to reveal the molecular clouds, not nearly as evasive as high galactic cirrus, but to do so with a "foreground" swarm of stars. Although I think I managed to successfully keep the stars from overwhelming the scene, I feel the dusty structures are a bit too much "in your face". You can see them, but can you "feel" them? Frame adaptation was also challenging, despite all frames were captured under similar, fairly dark skies (only the 1st night wasn't as good, but I retook that data on the 4th night, so that doesn't count).

In any case, it otherwise is a gorgeous field.

The nice touch was perhaps the red arch on the right area of the image, identified as SH2 133, which certainly adds a nice touch to the scene, otherwise dominated by dusty molecular clouds. The Ha also seems to extend further from the clearly visible arch, as if it was cradling 6 Cephei, the bright blue star on the left of the arch that also seems to illuminate some reflective dust around it.

Get a poster, t-shirt, mug, mousepad... with this image!



First DeepSkyColors Poster now Available

Posted: October 7th, 2010


Now you can buy an exclusive, high-resolution, Deep Sky Colors poster with some of my best images. The poster contains several award-winning deep sky photos, and best of all, you can choose from different sizes (up to 35" x 45"), printing media (regular, matte, gloss, UV, etc), or even frame it - whatever fits your needs.

Also, in order to make the poster a bit more special, I will stop the sale should it ever reach 100 copies sold. Um, what? If it reaches 100 copies sold, why stop selling it? some may ask... Well, I would simply make a different poster by then, but at least, those who purchased it will know that they own a poster where no more than 100 copies were printed and sold, that's it.

It can also be a great gift, not only for adults but also for children! Who knows... Maybe it'll spark that interest for astronomy that we all know so well!

To purchase a copy, click here!

Here is a low-res version of the poster.







Clusters, Hartley, and the Heart

Posted: October 7th, 2010



 

Text from NASA's APOD for this image:

An alluring Comet Hartley 2 cruised through planet Earth's night sky on October 8, 2010, passing within about a Full Moon's width of the famous double star cluster in Perseus. The much anticipated celestial photo-op was recorded here in a 3 frame mosaic with greenish comet and the clusters h and Chi Persei placed at the left. The well-chosen, wide field of view spans about 7 degrees. It extends across the constellation boundary into Cassiopeia, all the way to the Heart Nebula (IC 1805) at the far right. To capture the cosmic moment, a relatively short 5 minute exposure was used to freeze the moving comet in place, but a longer exposure with a narrow-band filter was included in the central and right hand frames. The narrow-band exposure brings out the fainter reddish glow of the nebula's atomic hydrogen gas, in contrast to the cometary coma's kryptonite green. In the past few days, comet watchers have reported that Hartley 2 has become just visible to the unaided eye for experienced observers from dark, clear sites. On October 20, the comet will make its closest approach to Earth, passing within about 17 million kilometers.



Hyades in the Dust

Posted: September 26th, 2010



Click here for a larger version

Sometimes, when I'm at a dark site, working on any given project, I run into "dead" times. Moments when there's no point in spending time shooting at my chosen targets. Perhaps because they're already too low in the sky, maybe because they aren't high enough.

When these moments are long enough, an hour, maybe more, I often improvise, and do a quick capture of "something" I haven't even thought of it... Many times these shots don't go anywhere. But sometimes, they marvel me.

This image is one of such. During one of the New Moon nights of September 2010, when I was done for the night working on a project, I improvised just a few shots to the Hyades, in Taurus, being this an area it has always interested me visually, despite it's not a usual astrophoto target.

The image bears very little data for astrophotography standards. All four filters gathered light for less than one hour combined. It's so little data because as I said, it was just something improvised to "kill" time...

So just about 1 hour of data, and just a bit longer spent on processing the image, rendered however what I feel is a refreshing view of one of the areas of the sky that, despite being quite visible, even to the unaided eye, at moderately dark sites, it has received little to no attention from the amateur astrophotography community.

Because this was the last unprocessed data I had at the time, when I calibrated and stacked the images at home, at first I was simply getting the image "done", but the moment I saw a hint of galactic cirrus in it (and as you may guess I always look for any faint signal the image may offer), I became interested! Considering the little time spend, I'm actually very happy the way it turned out.

The composition didn't aim for many goals either. I wanted to place the star Aldebaran at a location in the field of view that would support and balance the image. Not in the middle, but somewhere where it would give enough weight so as to become the "holding point". From my perspective I believe I achieved that simple goal.

This was the first image I processed only with PixInsight 1.61, from the very first stages of calibration, registration and integration.

As for the galactic cirrus (the faint background dust clouds), I have compared the field with its corresponding area from the IRAS survey and the background clouds match quite well, in some cases being virtually identical structures, so I have no doubt the signal is good. The only area that doesn't match is around Aldebaran: in the IRAS data you can see structures around it, but in my image there's just brightness and you cannot see any structures. Here's a screen shot of that area as captured in the IRAS survey, after placing dots over the location of the main stars, to better compare both images:

Get a poster, t-shirt, mug, mousepad... with this image!



Milestones and Accolades

Posted: September 20th, 2010


You're being redirected to the Awards and Accolades page, here in DeepSkyColors.com.
If that doesn't happen in 3 seconds, please click on the link.

Andromeda (M31) versus Triangulum (M33)

Posted: September 17th, 2010



This large panorama (a 3x4 mosaic) presents an unusual view that confronts two of the largest galaxies (as seen from Earth) in the night sky: the Andromeda Galaxy (M31) and the Triangulum Galaxy (M33).

The Andromeda Galaxy (top left corner) is a spiral galaxy approximately 2,500,000 light-years away, in the constellation of the same name. The Triangulum Galaxy (bottom right corner) is also a spiral galaxy, at approximately 3 million light years distance in the constellation Triangulum. The bright star in the middle is Mirach, a red giant star about 470 times as luminous as the sun and approximately 200 light years away.

Between them, and invading the entire scene, the often very elusive galactic cirrus clouds can be seen.

Because of the large field of view required to capture these two galaxies in one image, there aren't many images, if any, presenting these two galaxies in the same composition. For that reason, I find this image to be of unusual beauty as well as perhaps a bit thought provoking.

CAPTURING THE DATA

I had to go "at it" several times for several reasons, so in the end the image is a potpourri of data captured in Spain in August, at the DARC Observatory early September, and at the Central Nevada Star Party last weekend. Same scope and camera, but different skies, different exposure times, different amount of subframes, and in one case, even different binning! This mosaic has it all! (BTW I do NOT recommend messing up like that at all - there are "reasons" for all of this, it's just too long of a story :-)

The FOV can be captured - with the FSQ+reducer and the STL11k - as a mosaic of 3x4 (12 frames), but in reality I ended up shooting 26 different frames, each with its LRGBs... This is because once I was done with the data I captured while in Spain, I didn't like the final FOV, so I rotated it, and then I had to capture more frames to "fill up" the holes, then creating seamless frames became very difficult - first because I used different binning and timing, and second because adding frames to an already processed mosaic is often a VERY BAD IDEA. So anyway, I went again and captured more data at the CNSP last weekend to have frames that would match better when building the mosaic. Even with that, some differences can be obvious if you pay attention, but the only way out of it would be to retake the 3x4 frames that make up the FOV and process them all together at once (and I've rather move onto other projects).

GOALS / INTERPRETATION / FINAL FOV

I was hoping Mirach (the star in the center) didn't end up dominating the image so much. Knowing how bright it is and that it was going to end up in the middle of the image, this was wishful thinking, but in the end I think it balances the image somewhat ok - kind of like the mid pivot of a seesaw between the two galaxies. Not quite the effect I was hoping for, which was more the effect of "confronting" these two monster galaxies, with the added challenge that the galaxies are very far apart and the attention may get lost, not sure where to focus, and Mirach constantly becoming the safe harbor of our attention, but I think something can be made out of it. Or maybe I'm reading the image backwards!!

PROCESSING THE GALACTIC CIRRUS

The signal from the galactic cirrus is quite real, not artifacts, not gradients. As always, with very faint data, I cannot guarantee absolute precision in the light intensity differences, and only suggest that it's approximate. In any case, if we were to capture it deep enough, and in a perfect world, the cirrus should look a lot wispier than in this image. Instead, it looks more like a blur.

To see what I mean, if I do a heavy stretch on the raw data, I can tell the visible cirrus clouds are quite wispy. Look at this crop of one of the areas (top-middle, though the very top in this stretched image doesn't appear in the final image because it was cropped out):

(yes, in the above image you can clearly see one seam :-)

It would be amazing if this kind of detail could be brought to the final "pretty" image, but unfortunately it was very hard to do, for me at least (it's really dim stuff), so I settled with being able to bring the signal above the noise, but heavily blurred. Also I didn't have a lot of data, so I simply didn't have the know-how or the means of better bringing out this signal that was sitting right with the noise.

BTW the blur doesn't come from applying noise reduction but from separating large and small scale structures in the image. The "ŕ trous" wavelets tool in PixInsight however tends to produce this effect when you abuse it, and although perhaps there's a way to preserve some of this appearance by breaking and processing the image in more than 3 scales, I didn't experiment with that and instead went for what I already know how to do: breaking the image in just 2-3 scale layers (wavelet planes), operating on them separately and then adding them back, rescaling. 



From the Trunk to the Bubble

Posted: September 8th, 2010



The above image is a 3x4 mosaic (12 frames) I captured during my visit to Spain the summer of 2010, over 4 nights. It is in fact the very first astroimage I captured from Spain.

Beginning at the lower left, the large emission nebula is cataloged as IC 1396. Hundreds of light-years across and about 3,000 light-years distant, it contains a dark, winding, tendril-shaped feature popularly known as the Elephant's Trunk. Near the top middle, the bright nebula with an embedded star cluster is NGC 7380. At the upper right lies NGC 7635 (the Bubble Nebula) and star cluster M52.

Although the final result wasn't quite what I had envisioned, it's clear that this area is extremely rich and gorgeous - awaiting for a better representation!

 



Pinar de Araceli Star Party 2010

Posted: August 21st, 2010


[Photos courtesy of Jesús "Astrogades"]

The days of August 6~10 a bunch of amateur astronomers (visual and imaging) met at Pinar de Araceli, in the province of Granada, in Spain. This site was in fact a "short" 100 minutes drive for me, coming from Murcia (my hometown and where I was staying), but people came from all over Spain from places as far as Seville (4 1/2 hours drive), Cadiz (5 1/2 hours) or even Barcelona (over 7 hours drive), .

This was my second visit to the place this summer (and also my second visit ever), but it was the first large "star party" I was attending in Spain. Things are a bit different when comparing with the star parties here in the US, but I won't say which is better - truth is, there's no better or worst, each of them has their own charm. One thing common to both: comradery,  friendship and great atmosphere. One example of that came on the third night I spent at the Pinar. The first two nights were wonderful, but the third night the sky decided to go overcast by 11pm and yet, we stayed up until way past 4am talking and basically having a great time despite the sky decided not to cooperate.

The site is very dark, in the middle of nowhere, deep in the gray zone, and sits at around 6500 feet high. It's populated with around 30+ individual cabins that offer almost everything a home can offer. Here's a view of part of the area where you can see some of the cabins:

There's a restaurant nearby (property of the management of the site) where people gathered for a nice lunch, no BBQ but some really yummy stuff. There's no argument people here know how to enjoy a good meal even when far from civilization!

Not sure if this was a patriotic sign, some leftover paraphernalia from the recent Soccer World Cup win or "all of the above" :-)

The site even has a pool, a reminder you're far from everything but still can enjoy some "civilized activities" during the day (although the water isn't that warm even in the summer months):

Because the are is so large, imagers and visual observers actually setup at different areas. It's not a rule though, and as long as you respect everyone's night vision, you're welcome to setup anywhere you like. Even by your own cabin all alone if you want, of course! Here's a pic of a few scopes in the imaging area at sunset:

It looks like some imagers haven't discovered the benefits of turning red their laptop screens, something I was VERY vocal about during my stay and afterward. Fortunately these were just a few... Here's a night shot of another imaging area where you can see one of such bright screens. It even hurts me to see it in the photo but I think they've got the message. The background sky in the image doesn't do justice to the quality of the sky BTW, and of course, all those red lights you see is the result of a long exposure (there's no excuse for that whiteness in the middle of the photo though!).

The group picture was rather poor, considering there were over 90 attendees, but better than nothing!

Notice the absence of white beards! Yes, I'd say the average age of the group (disregarding kids) was probably between 30 and 40. That was kind of interesting, considering that at a typical star party in the US if you yell "hey you the guy with the white beard!" you may get over 1/3 of the people turn their heads! (ok I'm exaggerating here I know :-) Anyway, yours truly is #7 from the left in the above image.

If you wonder if I actually REALLY managed to bring all my gear over to Spain, here's proof:

Well, the EM200 mount was an acquisition I made while I was there. My EM400 was just too bulky to bring in the plane without paying an expensive fee, so it stayed in the US. The EM200 is pretty much a smaller version of the EM400 but for that type of load it was just as a performer.

Anyway... When I realized I was going to miss GSSP this year I was rather sad. GSSP is such an amazing event!! But I have to say that this "quedada" in Pinar de Araceli - along with a few other outings I did while in Spain - will be unforgettable. The site is amazing, the management are incredibly great people, and although I did miss a bit the "camping" feeling of other star parties such as GSSP or CalStar, I have to say that having a cabin full of commodities was a plus, not to mention the fact we didn't have to deal with batteries of course.

This time around the price couldn't be better: 20€ per person and kids free will give you a complete cabin for one night (min. two people). Compare that with the $200~$300 per night at Lake San Antonio cabins (which also are at an area close to nearby lights), plus the $20 per night for just entering the site. Actually, there's no comparison!

Another plus is that the owners of the site were so pleased with us, they've decided to accommodate a large paved area for future star parties, with parking space, setting up area, and even including a cabin right by that area, accommodated for our astro-needs (red lights only, etc). They'll be inaugurating this new area in another star party that'll take place either in September or October (I forgot) - this one I'll have to miss because in September I'm planning on going to the Central Nevada Star Party and in October there's CalStar.

Regardless, and although I probably won't be coming back for a while (the trip from California is a bit too long), I certainly plan to visit El Pinar every chance I get, and should I ever move to Spain, whether temporarily or permanently, I know that El Pinar de Araceli will become my preferred spot for astrophotograhpy, even in winter, despite the loads of snow the site gets in the winter (the area they're preparing for astronomy will be snow-plowed daily - it was originally a tennis/soccer field that was also getting plowed daily). Needless to say, if you ever visit Spain, especially if you're in the southeast, and are hungry for dark skies, El Pinar de Araceli should be one of your must-do places to visit. Oh, and tell them Rogelio sent ya! (I don't get commission BTW).

Wrapping up: A great star party, with great people, great site, great skies, and of course, images coming up the moment I get some time to process them. See you soon, PDA!




Between Sagittarius, Ophiuchus and Scorpius

Posted: June 18th, 2010



Click here for a larger version

When I drove a total of 1,200 miles to capture my widefield image of the IFN I thought I had gone too far and told myself I should control myself a bit. So when I calculated the total driving time for this image to be over 1,800 miles (and that's not including the Rho Op area on the left of the image - otherwise, add 800 miles to the 1,800!) I realized I didn't talk to myself clearly enough! :-)

The mosaic above is made out of 52 frames. If we take out the 12 frames from the already mosaic I had done of the Rho Op area, that leaves the 40 frames I captured and processed this month of June alone. Each frame is 3x5 minutes of L and 3x3 minutes each RGB, all bin 2x2.

I captured the data in 9 different nights: 6 outside of the DARC Observatory, 2 during a camping weekend in Plettstone (Bear Valley), and one additional frame catured at the back of the Lick Observatory. All during a period of around 12 days. Um, yes... I do have a DAY job too!!

As I mentioned earlier, the total round trip driving time to these dark sites added up to 1,840 miles driven. Total exposure time for the 40 frames is around 40 hours (48 if we count the Rho Op area) with a time in the field exceeding over 70 hours. The original image, over 18,000 pixels wide, can be provided upon request. It's just too big in size I'd rather not to pay the bandwidth toll (yes I pay for my bandwidth).

People familiar with this area will soon realize the image is upside down, and that's my favored composition. It gives me a stronger feeling as if the nebulosity in the Rho Op area is "escaping" from the Milky Way, although for those who must see it north up, I have a north-is-up 4000x2170 version here (2.1mb).

PROCESSING

A few comments about the processing, in case anyone's interested in the insanity involved in building a 52 frames mosaic and try to get it processed in barely 4 days.

Making the 52 processed luminance frames to match seamlessly wasn't easy. I had to give up three different methodologies, the first one being an effort of over 10 hours that I finally discarded. Finally, with the lightness data more or less registered seamlessly, doing the same with the color made the previous work on the luminance data look so easy! Throughout the whole process I used PixInsight, Registar and Photoshop, each of them with their advantages and disadvantages.

Mosaic'ing all red frames, then all green frames then all blue frames over the lightness mosaic didn't work well. You need a 100% perfect result on each channel in order for them to match later, Registar generated way off R, G and B registered frames. PixInsight was much more accurate (also much slower to produce) but still not perfect across the 40 frames (and the moment one channel frame is off, it;s all useless), so I registered and aligned each master R-G-B frame separately, gradient correction (remember, each frame is 5.5x3.5 degrees, which is going to generate much more severe gradients than on smaller FOVs), color balance, etc... 40 times. All this was done with PixInsight which has proven to me its registration process is almost flawless and better than anything else I've tried - including a trial version of CCDStack v2. Making the processed 40 RGB frames to register with the lightness data wasn't hard, but still a work of patience, having to do one by one, etc.

Some "purists" may criticize this methodology, as it requires the RGB data to be registered twice: first for each frame, then over to the (lightness) mosaic. All I can say is... Let me know how it goes when you process your own 52 frames mosaic using more "rational" approaches. And I'm not being entirely sarcastic here - I would really like to know how it goes! I did what I could make it work, and out of the different approaches I tried, this is the only one that worked across the entire 40 frames, and it's because of that I can now say that this mosaic has a nearly perfectly seamless lightness data - no funky stars around the seam areas, and each tiny little star tat shows color it's because the RGB channel data gave that color to that tiny star and such data matched 100% accurately over the lightness data. No other methodology I tried gave me that over the entire field. Maybe I goofeed off, I don't know...

Anyway... But of course, once I had the RGB mosaic nicely aligned, despite it matched perfectly with the lightness data, the color from frame to frame was showing quite some differences. How did I process the color data to generate an almost seamless transition? Basically by doing individual adjustments one frame at a time, repeat, repeat, etc. As if it wasn't enough having processed 40 frames individually, I just couldn't see having the color to match seamlessly.. Because most gradients had already been taken care of, color information was uniform, so all adjustments were mainly applied over each entire frame without the need to create individual masks.

In the end, other than 3-4 frames for which the original data was pretty bad and there wasn't much I could do to save them, I managed to get things to match more or less seamlessly.

With all that done, and the L and RGB composites done, the final processing on both was very simple. I know I could improve it if I work on it a bit more, but I'm heading for a trip and I wanted to post what I've got so far, which, with all its defects and so on, it's no small effort. I hope you like it!

Get a poster, t-shirt, mug, mousepad... with this image!