ISS passes for Chicago

UPDATE 7/06/2009: Here's the current set of passes.

There are another set of convenient evening passes of the International Space Station over Chicago until the end of the month. Last night we watched it streak across the sky in five minutes from Ryerson. Through the telescope at low power it was two blazing white ovoids with two small orange dots on one of the white blobs.

Radio astronomy dish raising

Joe Cottral managed to get a spare 2.5m satellite dish from western Illinois to Chicago. The rest of the RAS had the responsibility of getting the dish from ground level up to our 6th floor aerie. We decided on raising the dish as reasonably quickly as possible, to reduce the annoyance factor for all non-involved. We also picked after much observation and discussion to raise the dish via the southeast corner of Ryerson which is an elevated turret. The reason being the turret allowed easy transfer over the parapets of Ryerson. The loading dock offered easy vertical lift, and the fire escape offered quick one-story lifts, but in the end, Lui's suggestion of the turret was the superior option.

Now, we have to 1. acquire a receiver capable of 1420MHz and 1.6GHz-ish, 2. Clean up the dish mounting steel, 3. Mount the dish on Ryerson with lots of Quikcrete, 4. Get microwave-capable cable, 5. get a low-noise-amplifier, and 6. put it all together. Minor bit there. Oh yes, and decide where to place it on the roof.

42 Orionis nebula (NGC 1977)

Click to enlarge. A total of 53 images, each 15 seconds each, totaling 13:25 minutes. Taken on December 29th, 2008.

42 Orionis is a bright B1 star in Orion's sword, just to the north of the spectacular Orion Nebula (M42 & M43). It is always overshadowed by its neighbor and many miss the NGC 1977 nebula entirely because the Orion Nebula is almost always glowing in the field of view and very distracting. NGC 1973 is the nebula surrounding the star in the upper right of the frame. 42 Orionis itself is the bright star just to the right of center. The bright star to the left of center is 45 Orionis, an unrelated foreground (370 ly away) star. Unwritten is that this nebula is part of the same giant Orion Molecular Cloud complex that the Orion Nebula is part of.

As always, I am never happy with processing. On this one, there were a significant number of sub-images that were trailed. Normally I align all the subframes and then add the subs together. Since adding will send the pixel values all to 32767 (I use Iris, which is limited to 16 bits), in most cases I utilize either a median combine (which will get rid of the trails) or use "add_norm", which normalizes the final result to fit in 16 bit space. However in this one, I first multiplied all the values in all the images by 0.02, then added them all up, then I subtracted the images I knew were trailed. Some modified equalization and a touch of gamma, and all done. Until I am unsatisfied again.

Moon mosaic

A moon mosaic from last night. I didn't take the images or process them; Will did all that. The only thing I've done is run it through Autolevel in Photoshop. For processing, we took about thirty images each of each section of the Moon with the SXV-H9 camera at 1/1000s, and then ran each set through Registax to get the sharpest ones, then used Autostitch to put the sets together.


Click to enlarge.

Moon, Icicles, and the observatory

Click to enlarge

I showed some RAS folks how to use the CCD camera last night. We couldn't get the drivers installed on the new laptop, despite tweaking the INF files to identify the USB device (at least in Windows, when you first connect a USB device, the device sends an ID number down, and Windows looks in the INFs to locate the driver). Unfortunately the manufacturer of the Starlight Xpress SXV-H9 camera changed the camera and the driver without changing the name or offering the old driver for download--the result is old camera owners can't get it working at all. Having to ask for the driver when it could just be on a website someone is really dumb.

Anyways, we got the camera working on the ancient soon to die laptop (94MB of RAM!) and took this 3 minute (12x 15sec) exposure of the Dumbbell Nebula. Enjoy.

Watch the clouds go by

See the clouds go by at night at http://skycam.uchicago.edu/. It's a field of view 30x50 degrees pointed south at about 50 degrees up.

Match your local light pollution by seeing what you can see in Orion. Ryerson is somewhere in magnitude 3.

Messier 15 from last night

We had a nice clear evening last night and took some photos over at Ryerson Observatory. I processed one last night real quick like. This globular cluster is M15, in the constellation Pegasus.

M15. 23x5seconds, 0.25m f.6, Starlight Express SXV-H9. Processed in Iris

We also took images of M2, M31 (Andromeda Galaxy), Comet Holmes, and Neptune (including Triton!), but I'll have to process those.

Comet Holmes from Chicago

We had a great clear Monday after the RAS meeting so we got everyone to come up to the observatory to see the great outburst of Comet Holmes. Photometrically it seems the same brightness, but in binoculars or in the telescope it's much bigger and fainter than a few days ago.


Comet Holmes at Ryerson Observatory. 36x5s exposures, 0.25m f/6.

We imaged it through our 10-inch reflector while looking at it through the six-inch refractor. I processed the images to match the visual look. This comet is so bright I was able to take reasonable images with my digital camera just pointed at the eyepiece, with a few seconds of exposure, but I can't find my memory card reader, so those will have to wait.

So--it's still naked-eye, and now obviously not a star, so get out and take a look--the lower right "star" of an isoceles triangle containing Mirfak, above the bright star Capella in the northeast. (See a finder chart here).

A lot of people were asking details about why exactly the comet increased in brightness a millionfold. Without reading further, I vaguely heard a suggestion that the heat from perihelion takes a while to move deeper into the comet to where there is still volatile ices to blow out. Right now, the comet is moving out between Mars and Jupiter.

A fantastic historical read is Fred Whipple's paper in Icarus, volume 60, issue 3: "Comet P/Holmes, 1892III: A case of duplicity?" (link may need a subscription). I quote:

It may be added that the comet was discovered as a bright object nearly 5 months earlier than its perihelion passage, although the observing geometry was favorable all the time (at perihelion, the comet should have been only 1.5 mag fainter than near opposition 5 months later). It was also the first short period comet of q > 2 ever discovered.
Barnard's 1913) description on November 9.2 at Lick Observatory is revealing:
"'Its appearance was absolutely, different from any comet 1 have ever seen--a perfectly circular and clean cut disk of dense light, almost planetary in outline with a faint, hazy nucleus and a slight condensation some 5 seconds south following the nucleus (brightness -- Andromeda Nebula, diameter 260" at 8h0 '" P.S.T. and 286" at 9h40"').'" He observed the comet to brighten perceptibly by the next night at which time he saw an outer faint diffused envelope some 12' (800,000 km) in diameter.
Barnard's description carries great weight because he was a superb and experienced observer, having already discovered 15 comets and observed many more. His comments were generally confirmed by many other observers over thc world. Interest in the comet flared as the comet burst again to nearly naked eye brilliance on January
16, 1893, after having laded some 5-6 mag by late December and early January.
On subsequent returns P/Holmes hits remained extremely faint and inactive.

• Circular -- check


• Sudden nearly naked-eye burst -- check


• Andromeda galaxy reference -- looked at Andromeda tonight right afterwards -- check


• About 10 arcminutes in diameter -- check

Don't read anything into his comet satellite hypothesis though.

Reading further back, Bobrovnikoff wrote in 1943:

The comet was not well observed in December, 1892, and in the first part of January, 1893. On January 16, Palisa, in Vienna, found with the 27-inch refractor, instead of a diffuse comet of 10th or 12th magnitude as expected, a yellow star of 8th magnitude with an envelope of 20" in diameter. The comet increased in brightness the next day and could be seen with the naked eye. After January 18 it began to decline in brightness, and by the beginning of April it became very faint.

50th anniversary of Sputnik

Things have been very busy and as a result I've been unable to post--but today is the 50th anniversary of man's entry into space with the launch of Sputnik. Last night the visitors to the Ryerson Astronomical Society's Wednesday viewing saw the largest satellite (artificial) in orbit: the International Space Station, as it rose above the horizon, passed Jupiter, and went into the Earth's shadow. Tonight in Chicago, you can see it twice, once at 6:57PM and again, once around the Earth, at 8:30PM. Details are always at Heavens-Above.

P.S. It's also World Space Week. Go to the RAS lecture on Monday about Sputnik.

Mercury, the Moon, and Venus

As I mentioned in my last post, more images from the evening of May 17th.

You can see the Moon--but look closely at the support wires on the left side of the crane--see Mercury?


Through the telescope, the autofocus picks up the high contrast of the crane--and makes Mercury a round blur.


Forcing the focus to Mercury.


Venus, much higher up in the sky, but still subject to atmospheric dispersion.


You can see the turbulence by viewing this video of Venus here (753kB, 0:17 WMV).

The wide view.

The young moon

The 29 hour-old moon was beautiful last night, and just a few degrees away was a suprisingly bright Mercury.




Composite of two images.

Both were taken through the Ryerson 6-inch refractor and a Canon A540 camera. I have more images--will post them as soon as I finish processing them.

A new exoplanet from HAT

Last December four members of the RAS were lucky enough to spend four days at the MMT/Fred L. Whipple Observatory located on Mt. Hopkins south of Tucson talking to researchers and observers. One of the systems located at the "Ridge" area of the mountain was HAT, the "Hungarian-made Automated Telescope", a collection of small scopes there at Mt. Hopkins and in Hawaii. Gaspar was too busy working to talk to us, but we now know why. The collabration has discovered a huge exoplanet orbiting HD 147506, an eight-magnitude star 441 light-years away in the constellation Hercules. It's about an eight-Jupiter mass planet in an eccentric short 5.63 day orbit around a hot F8 star, and it's as dense as a terrestrial-style planet! It was discovered because from Earth, its orbit crosses the face of the star. The next transit is tomorrow morning (from here in North America).

http://adsabs.harvard.edu/abs/2001PADEU..11..107B

Yerkes Observatory trip

The Ryerson Astronomical Society sponsored a trip up to Yerkes Observatory this weekend. We split the 60-odd visitors into three groups and showed them the observatory through twilight. I got to show them the basement and the 24-inch reflector--fairly mundane things, and there is only so much you can opine about the difference between astronomy and astrophysics three times in a row. So, while talking about the infrared camera called HAWC on the second-generation flying telescope called SOFIA, scheduled for its first test flight today!, I tried my best to talk about light outside of our visible range. And I had to bring up near-infrared radiation and took some examples with each group. The above image is from the next morning. Everyone hopefully had fun looking through all the scopes, including the world's largest refractor, at various targets. Halfway through the observing I moved the 24-inch onto Messier 51, the spectacularly interacting galaxy pair in Canes Venatici, just off the handle of the Big Dipper. I would say some two-thirds or more of the visitors saw the spiral arms. After the big group left, the overnighters returned to the 24-inch at as M51 was transitting, the arms were much more evident.

(An example from Ryerson Observatory of M51).

The lunar eclipse

Chicago got a mostly cloudy eclipse--we never saw it fully eclipsed and only had glimpses as the Moon left the Earth's shadow. Here's a sample of what it looked like from Ryerson Observatory:

Carl Sagan

Carl Sagan died ten years ago today. Has it really been ten years? I guess I can say it has: new visitors to Ryerson Observatory often do not know who he was and miss some of the symbology of the one-hundred-and-six-year-old refractor they are peering through. What they don't realize is how important he was not to the advancement of science, but to public science education.

He was a student here at Chicago; he was, as the picture indicates, president of the University of Chicago Astronomical Society (now known as the Ryerson Astronomical Society). After his short stay in the college he went to the Astronomy department and left a Ph.D. I quote a visit from John Musgrave, a member of the Society, to Yerkes during Sagan's period there:

I remember the one Yerkes night we had that fall (1958): it was cloudy; 
but if it had been clear we could have used any of the telescopes as no
one was using them for research - no one on staff greeted us - just some
"lowly grad students".  Rather than observe we heard a lively spur of
the moment lecture by a post-doc introduced to us in somewhat apologetic
tones -  "we don't know if he is for real or not" - unusual even by U of
C standards. It was Carl Sagan and he spoke about the possibility of
extraterrestrial  life (maybe other things as well - but with Carl I
remember the performance more than the content - including waving
arms).  I guess the "we aren't really sure about this guy" label haunted
him through to the end.

I often wonder what the dismal atmosphere of a coal-smoked Chicago was like for astronomy in the early fifties--and whether the old cranky telescope (fifty-two years old then, in 1952) did anything to inspire future thoughts. His logs are short, and there never seemed to be much observing or possibility of observing. See here for a scan of a sample logbook page. Or here for the entire text of the 1952-1964 logbook.



A member of the club in the seventies, when Sagan was back on campus showing off images of the new Viking landers on Mars, got him to sign the logbook yet again. I never met him, but a fellow RAS member at the time, Chris Conselice, was in attendance when they created a graduate student award in the astronomy and astrophysics department. He said he looked quite frail--this would have been 1995 or 96.

Keay Davidson in his biography, "Carl Sagan: A Life", writes:

And atop Ryerson Hall, he and a band of future astonomers learned (with the guidance of the astronomy club advisor, Guy C. Omer Jr.), how to operate equipment in the campus observatory. Other club members included Tobias Owen, who, like Sagan, would go on to a distinguished astronomical career. Sagan ran the astronomy club's "theoretical" section, and arranged speeches by famous professors such as Subrahmanyan Chandrasekhar.

Omer "taught me how to make the right ascension and declination drives go, and gave me a key to the observatory... and so there I was: I could go and look at the stars if ever there was a clear night in Chicago," Sagan later recalled. Yet he wasn't much of a stargazer. The club's logbooks show that Owen and several other members showed up night after night, for years, to meticulously record their observations. But Sagan observed only seven nights between October 1952 and November 1953; and when he observed, he left only terse notes. One searches the logbooks in vain for early fragments of Saganish eloquence. His most vivid entry dates from 2:15 to 3 AM on November 25, 1952, during his sophomore year: "Some [cloud] openings; then clouded over. Also COLD."

...

"Much more important" than stargazing, he later joked, was that at Ryerson Observatory, "I could bring young women to a place where could be undisturbed--which was far and away more important than being able to look through the six-inch telescope!"

In that spirit I leave you with this cartoon from the 1957 Cap and Gown. (My notes have it mislabeled as 1953--it could be 53 or 57, it matters not):

Saturn, the Moon, and Ryerson

After the Ryerson Astronomical Society meeting Monday night, Steven, Katie and I went up to the dome and observed on a nice clear night.

Saturn.

The Moon

The Moon aesthetically framed.

The telescope looking at the Moon.

Steven at the controls.

Ryerson office background radiation

Steven conveniently graphed the data from my geiger counter, covering a week in the Ryerson Astronomical Society office. http://gateway.spc.uchicago.edu/~stevenl/cosmic/

Ryerson Dome at night

Steven was trying to observe an asteroid occultation at that moment.