What is going on with the Herschel and Planck missions?

The European Space Agency launched an ambitious set of satellites a few days ago: Herschel is a 3.5m diameter infrared telescope, and Planck is a cosmic microwave background telescope. Both are planned to be placed in one of Earth's Lagrangian points called L2. Upon launch such large objects can be tracked with optical telescope for a while. Upon examining these images, astronomers found not two objects, but at first four, which turned out to be the booster rocket and the structure holding both satellite while launching (see here). But later, they found two more fainter objects. These objects have seemingly moved off of the Herschel/Planck trajectory. What were they? The other more disturbing news came today, when Jean-Claude Pelle of Southern Stars Observatories reported finding dozens of new objects in the same path. This implies a possible failure of one or more of the telescopes and would be a blow to science.

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.

Go see Comet Holmes.

If it's clear where you are, go outside right now and see Comet Holmes with your eyeballs, even with a nearly full moon nearby and even if you live in a horribly light polluted city. Binoculars will help, but you can see the comet with just your eyes right now, although it looks just like a star.

Look to the Northeast. Capella is the bright white star. Look up further towards the zenith to a compact triangle of stars, with the brightest star on the top apex. That star is Mirfak. Comet Holmes is the one on the lower left, the one closest to the line between Mirfak and Capella. Tonight, Capella and the moon form the bottom two points of a skinny-ish trapezoid, with Mirfak and Algol the top two.

Binoculars will reveal the star as a glowing blob, much bigger than the nearly stellar yellow object I saw on Wednesday. A telescope will reveal a stellar nucleus and a glowing blob surrounding it, getting bigger every day.

Finding charts (albeit poor in magnitude distinction are here). Sky and Telescope has one too--just move Capella up higher in the sky the later in the evening. A report here

Pretty picture of the day

A dye laser points the way for the VLT towards the center of the galaxy.




Grab the huge versions of these at the ESO press page.
Seen via Astronomy Blog

Comet McNaught

Last night it started clearing up right near sunset, and through scattered clouds I was able to see a blazing new comet, C/2006 P1 McNaught, near perihelion. A bright coma and tail was visible golden deep in the murk of the western horizon. It reminded me much of Comet Hale-Bopp, except H-B was that bright and in a dark sky--this one is only 10 degrees from the Sun.
This picture is a view through a six-inch refractor at approximately 40x, taken afocally (aka put the camera up to the eyepiece).

How to find it

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):