We started to get a naked-eye view of Comet 17P/Holmes last week, after it underwent a transformation in which it apparently ejected a huge cloud of gas, much of which is CN and C2, and NH2 molecules, and which are fluorescing. Unless you knew it, you would think it’s another star in the constellation Perseus, about half way between Cassiopeia and the Pleiades in the northeast sky in the evening. With no moon now and clear skies in Northern California, I got this shot with my little Canon Rebel on a tripod (with a 300 mm Tamron lens, 10 sec exposure at f/4.5):
Looking at it with binoculars, it it hard to resist the urge to try to focus it! But it’s just a big fuzzy ball…
The comet is on its way out of the inner solar system, having made perihelion last spring. The gas cloud has expanded to 70% of the diameter of the sun.
November 8th, 2007 at 2:09 pm
It is pertinent to realise that this comet is more or less at opposition, which is why it is near the meridian, directly overhead, at around midnight, it is in the north-east sky earlier in the evening. Therefore its tail will be flowing away from us explaining why we only see a ‘fuzz-ball’. The tail is just beginning to show now see: ” Comet Holmes Grows a Tail “http://antwrp.gsfc.nasa.gov/apod/ap071105.html.
The interesting thing about the comet is the gas cloud was ejected, spherically while the comet was going away from the Sun, therefore some underground cavern that had been sublimating on the approach to perihelion must have given way but only after maximum heating stress.
Garth
November 8th, 2007 at 3:07 pm
Nice photography!
I’d totally forgotten to go out and look for it, as it was overcast all last week, but I’ll be sure to get my giant binoculars out tonight.
November 8th, 2007 at 8:49 pm
Actually it was about two weeks ago (Oct 23/24th), it brightened by ~1 million times (from ~17 mag to ~2 mag) in some hours. Not many celestial objects can do that …
http://aerith.net/comet/catalog/0017P/2007-mag2.gif
November 8th, 2007 at 9:32 pm
I saw it myself 2 nights ago..beautiful…
November 9th, 2007 at 5:11 am
Is it possible to see it in the Southern Hemisphere?
November 9th, 2007 at 7:11 pm
Very nice shot. What is the model# for Canon Rebel?
November 10th, 2007 at 10:01 pm
A bit off-topic: See this fabulous talk by Carolyn Porco, leader of the Cassini mission‘s Imaging Team.
November 11th, 2007 at 12:52 am
I had a hard time seeing it because of the light pollution here in Minneapolis/St. Paul and the full moon. I did appreciate the coverage by Phil Plait.
November 12th, 2007 at 7:51 pm
Are you sure this is the same comet???? ie that made perihelion last spring.
The comet is on its way out of the inner solar system, having made perihelion last spring. The gas cloud has expanded to 70% of the diameter of the sun.