Sunday, October 14, 2012

Seeing the light in the dark

I just returned from Portal, AZ where I spent two nights with very good friends observing under some of the darkest skies in the western U.S.  I have blogged previously about Portal and what a great place it is to relax by day and observe by night, and this trip was certainly as rewarding as any.  We camp out at one of the premiere observing retreats known to amateur astronomers, the world famous Rancho de Farrar.  The early days of Rancho de Farrar are mostly unknown, however, historians have accepted local legends of it's beginnings...stories that seem to center on bonfires, whiskey, and heavenly bodies.  Speaking of amateur astronomers, below you can see our group of heavenly bodies as dusk settles over the ranch.   From left to right: Chris H., Shak (the 20 inch Dobsonian), Mike W., yours truly, Bill G., and El Jefe of the Ranch, Jerry F.

Folks living in places like Arizona are fortunate in that we often have clear views of the eastern horizon after sunset and can appreciate the beautiful colors of the "Belt of Venus."  The distant horizon and clear dry air in Portal combine to show beautiful colors as night approaches.  The blue color just above the distant hills is the shadow of the Earth being cast on our atmosphere and slowly ascending as the Sun continues to descend below the horizon.  As we say, often seen, rarely noticed!

Last week I acquired a very nice lens for my Canon T2i, a 15-85 mm EF-S.  I had wanted something that I could use to walk around with that was of higher quality than the kit lens, and also something that had a very wide field so that I could try to take some shots of the night sky.  I quickly learned that one of the most difficult parts is focusing the lens on the stars.  Simply turning the focus to infinity results in blurred stars, and there seems to be a sweet spot not quite to infinity.  The images of the milky way are far from perfect, however, I am  happy with them given that they are simply single shots, 25 seconds each with the lens at the 15mm setting...and that these are really my first attempts at this kind of photography from a dark site.

At left is an image of the Milky Way running nearly vertical into the foothills of the Chiricauhua Mountains.  This was taken at ISO 6400.  It is somewhat noisy, yet that is currently my trade off for obtaining the most color in the Milky Way.  Another reason why I need to get back to learning how to use Photoshop.

Below is an image of the Milky Way with a different composition, and I am not sure which I like better...And if you are a faithful reader that is not much into astronomy, I should point out that the reason that Milky Way is so bright in the south, is that we are looking toward the center of our galaxy in this area of the sky.

The image below was taken from a bit further back of the Ranch in order to capture some of gear.  It was also a 25 second exposure, but with an ISO of 3200.

 This next picture is a bit higher up in the sky and shows the Milky Way as it runs through Cygnus and the asterism known as the "Summer Triangle"

Despite all these pictures, I spent quite a bit of time looking through the telescopes that we had assembled within the circled wagons on the ranch:  a 20 inch Dobsonian, two 12 inch Meade SCT's, an 8 inch Celestron orange tube SCT, a TEC 140mm refractor, and a Zeiss 62mm refractor.  Truly, it was an embarrassment of astronomical riches.  And while we all enjoyed the various views, Mike was in and out of the "command center" where he was checking in on the data streaming in from his remote imaging set up.  Soon, I expect he will post a very impressive image of M 33, the Triangulum Galaxy, on his blog.

While he was imaging M 33, we observed it in nearly all of the telescopes on the field, save the 8 inch.  In my own 12 inch SCT I was blown away by details I had previously not seen in this low surface brightness galaxy.  Instead of the usual broad "S" shaped galaxy with two arms and a handful of bright knots, I was able to observe two additional spurs (arms) of the galaxy and more bright HII regions than I had ever seen.  Realizing how transparent the night was I pointed the scope at M 31, the Great Andromeda Galaxy and was again stunned by the detail.  Two dust lanes were easy and the edges of the lanes hinted at a mottled structure.  As I panned around, I was awestruck my M110, a satellite galaxy that is undergoing a merger with Andromeda.  As I pushed the magnification up to about 235X there was clearly mottling to this galaxy, and the bright nucleus was offset from center.  As I continued to observe  I realized that the reason the core seemed offset was that I was detecting an elongation of the galaxy back toward Andromeda.  This "light bridge" was confirmed by both Bill and Jerry.

I have been observing comet 168P/Hergenrother on and off over the past week and wanted to take a look at it from Portal.  I was not disappointed as the comet sported a stubby fan shaped tail- yet with averted vision there was clearly a long stream heading to the SE.  You can see this stream in my sketch at left, although it appeared fainter than in my drawing (obviously).  In addition to the comet, we observed a faint galaxy in the field of view, which Chris identified for us as NGC 7777, a 14th magnitude galaxy.  How dark was it last night?  We were able to detect this galaxy with averted vision in the 62mm Zeiss!  Had we not known it was there it would have been missed, however, with patience we were all able to tease it out of the background.

Another target that I had been planning to observe was the Veil Nebula, using my TEC 140 and an OIII filter.  With inspiration from the website of Steve Gottleib and using the chart at right I was able to observe many of the various labelled components.  I started at the "Witch's Broom" NGC 6960 and was able to easily identify the knot labelled 'D'.  I then moved back up to Pickering's Triangle also known as Simeis 3-188 and enjoyed the ethereal structure of this region while training my eye to pick out the fainter regions.  I then panned south and was able to detect the brighter portion of the "Thin Thread" as well as the knots labelled 'J' and 'I'.  I then relocated to the eastern portion of the Veil, NGC 6992 and 6995.  This is my favorite section of the nebula and my most traveled.  I made a point to observe IC 1340 and then located the star that would serve as a marker for knot 'A' which is Simeis 3-210.  This proved to be a little tougher than I expected given the glare from the star, but after careful observation I was able to positively identify the thin wisp of nebulosity.  Again, both Jerry and Bill were able to confirm this observation.

As the night wore on, we observed many targets from the popular Messiers, and double stars to interesting Arp galaxies, and of course Jupiter.  One of the highlights for me was Chris locating Comet 2012 J1 (Catalina) in the 20 inch despite it being close to the "Dob Hole" near the zenith.  This comet is cruising through Pegasus not far from Hergenrother and is approximately magnitude 14.5.  I had attempted this unsuccessfully in the 12 inch SCT.  I spent a few minutes revisiting some planetary nebula that I had observed from Portal two years ago with my buddy Christian (now back in Eurpoe), NGC 246 in Cetus, and IC 5148 in Grus  See this post for sketches of these objects.

Finally, a picture that was hard to take and that I had to mess with in photoshop to try and bring out the subject.  It is an attempt to image the Gegenschien, which is actually sunlight, back-scattered by interplanetary dust.    This soft glow forms opposite the Sun within the zodiacal light band and is only subtly brighter than the sky.  This is a phenomenon only visible under the darkest of skies.

All in all it was another great trip that ended all too quickly.  As great as the skies and observing are, it is the great friends and the unparalleled hospitality of the proprietor of Rancho de Farrar that make the trip.


  1. Wow! Nice. Not sure if I have seen the Gegenschein before. I believe, Dean Ketelsen showed me in 2010. Probably no chance from my observing point in Germany.

  2. Hello Christian-

    You have seen the Gegenschein Portal! I remember as it was the first time I saw it, 2 years ago in October, with you. Same night we observed IC 5148 in Grus...and I thought you took a picture of it? Anyway, my memory is not what it was even yesterday...

    Congrats on finishing the planetaries by the way!