Astronomy events schedule

George Jones

Saw it last night with my 15x70 binos. No tail, but still very nice. Looks like a star with unaided eyes.

George Jones

I just showed the comet to my wife. She was amazed that something out past the orbit of mars could appear so bright and big.

chemisttree

I just saw it last night. It is a quite bright fuzzy star to the unaided eye. Looks like a glowing pom-pom under even modest magnification (20X), but very bright. It looked just like this.

Telmerk,the Magician

Due to the clear skies in the last few night, a large amount of nice images has been taken by Hungarian astronomers about the comet outburst.

Take a glimpse if you feel interested:

http://hirek.csillagaszat.hu/aktuali...mes_kepek.html

I think that this page will be refreshed during these days. I hope that after the 2-3 cloudy nights we will have again the possibility to view the re-designed Perseus !

Saladsamurai

I am pretty sure that I got this comet in my view tonight...but I couldn't get much more than a "greyish fuzzball"....

Out of curiosity, how long does an 8" Newtonian need to cool to ambient temp. it was about 26 degrees F tonight. I wonder if that is why I couldn't see it so great?

Casey

Orion1

What would cause a sudden steep decrease in a comet's visual magnitude?

Did the comet experience a ice-gas phase 'flash point' with reference to Sol?

If a fraction of a comets surface ice were to suddenly flash into a gas, this would increase the volume and density of its gas envelope and immediately decrease its visual magnitude, would it not?

Or are we examining a type of comet-asteroid collision in space?


Reference:
http://www.aerith.net/comet/catalog/0017P/2007.html

chemisttree

Aim you telescope at a bright star (like Vega) and put in your shortest focal length eyepiece. Do you see concentric rings around the star just inside or just outside focus? If you do, you have all the resolution you need to view the comet... probably much more.

The comet is dimming out significantly now. The image I see through my telescope is a dim fuzzball, but the nearby stars are still pinpoint and bright.

Saladsamurai

I have no reason to belive that my telescope is out of collimation, so it must be because it is dimming :(

But I will check the collimation again and try again tonight. Roughly, how long do you let your scope cool on a night that's around 30 Fahrenheit before you attempt viewing?

Casey

chemisttree

I have a small refractor and a small 4.5" reflector so my experience wouldn't be of much use to you. I would guess that 45 minutes would be more than enough time to cool the telescope down enough for this purpose. Russ or Chronos would have better info for you, I think.

If the telescope hasn't cooled sufficiently, you would see that with the star test. And you probably shouldn't try to recollimate a telescope that isn't at thermal equilibrium.

Saladsamurai

Point taken. I'll give it a good hour before I try the comet again tonight.

Thanks chemistree,
Casey

Astronuc

http://news.yahoo.com/s/space/200801...iterandthemoon

russ_watters

Sorry I missed this before (I rarely check this thread). A "greyish fuzzball" is all the comet is. And in a telescope, even at low power, it covered most or all of the field of view. Here's a picture I took of it through my lower power/wider field of view telescope:

http://www.russsscope.net/images/Holmes.jpg

It looked about the same through the eyepiece (not quite as bright or well defined, though).

Saladsamurai

Nice. Thanks russ. Hey, I just noticed nuc's post about venus and jupiter. I would like to check it out, but I have been reluctant to go out since its freezing in Boston area as of late.

I was just wondering, is there any kind of damage that can occur to my scope due to sub-freezing temperatures? I know I would have to leave it outside for some time to cool the mirror. If not, is there anything to look out for? Like when I bring it back inside to the warmth. Do things get dewey or anything like that?

russ_watters

Dew is the thing you have to worry about most. Make sure you put the lens caps (don't forger the one on the eyepiece socket) before bringing it inside. It can also be a problem in spring and fall if you leave the scope out all night - it could be dripping wet in the morning.

For actually using it, the cold can make grease more viscous and can play games with the electronics, but neither of these cause permanent damage.

Saladsamurai

Cool. There are no electronics, so that is a bonus!

Saladsamurai

I heard there is a partial lunar eclipse tonight. I am going to Google around now to find the details.


EDIT It's a total eclipse. . . here is the link
http://sunearth.gsfc.nasa.gov/eclips...2008Feb21.html

NLocke

This years national dark sky week is March 29 to April 4.
To find out more about National Dark Sky Week, visit http://ndsw.org/