|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
ASTRO: IC 1613 another dwarf galaxy
As should be obvious by now I like these guys. Though I'm running out
of big and bright ones visible from 47N. This one is in the local group. I could find no consensus on its distance. This is odd since most references indicate it was used to help calibrate the cephied variable standard candle. The only one I found with an error bar put it at 2.38 +/- 0.07 million light years. So I'll go with that one. That puts it a bit closer than M31. While it is sort of in the general direction of Andromeda (south nearly 40 degrees in Cetus) it isn't associated with it that I have found. This was again taken with my severe ice problem and seeing this low (if the celestial equator region is low) over the lake put it right into my area of bad seeing and heavy fogging from ice in the air over the lake. You could see it rising up off the lake. I binned 3x3 rather than my usual 2x2 in an effort to get enough signal to work with compared to the ice. Oddly, while the fogging was severe it was pretty even with not as much of a gradient problem as I have higher in the sky with less ice to look through. I don't understand it but sure do appreciate it! References I saw say there are HII bubbles all over this guy. But I wasn't able to image but a few in the area to the upper left. Though there are a lot of hints of pink throughout the horizontal arm. This may be noise rather than true signal, I just don't know. I was only able to get 1 frame of color for each color before the fogging go so severe I had to quit (was hitting 40,000 ADU in 10 minutes which puts the fog into my non linear range as well as all the details in the galaxy. That meant my standard galaxy curves wouldn't work and I had to figure out new ones. One color frame isn't enough for something this faint. It took 5 nights to get the data I did then the clouds moved in and have not left since. Due to the intense fogging this is a rather noisy shot. I was going to get more data on it this month but the clouds had other ideas It is now on the way down and will not again be this high in my dark sky until next fall so this will have to do for this year. 14" LX200R @ f/10, L=7x10' RGB=1x10' all binned 3x3, STL-11000XM, Paramount ME Rick -- Correct domain name is arvig and it is net not com. Prefix is correct. Third character is a zero rather than a capital "Oh". |
#2
|
|||
|
|||
ASTRO: IC 1613 another dwarf galaxy
Bright image even with the ice/fog problems.
I did a quicky image of this galaxy in 2006 and found a distance of 24 mly. On checking the source, I found that I had mis-interpreted the data which listed a adjusted cephied magnitude distance as 24 (m-M). Battinelli et.al. (2007) suggest it is indeed a satelite of M 31. http://adsabs.harvard.edu/abs/2007A%26A...466..875B On Sat, 29 Dec 2007 00:08:46 -0600, Rick Johnson wrote: As should be obvious by now I like these guys. Though I'm running out of big and bright ones visible from 47N. This one is in the local group. I could find no consensus on its distance. This is odd since most references indicate it was used to help calibrate the cephied variable standard candle. The only one I found with an error bar put it at 2.38 +/- 0.07 million light years. So I'll go with that one. That puts it a bit closer than M31. While it is sort of in the general direction of Andromeda (south nearly 40 degrees in Cetus) it isn't associated with it that I have found. This was again taken with my severe ice problem and seeing this low (if the celestial equator region is low) over the lake put it right into my area of bad seeing and heavy fogging from ice in the air over the lake. You could see it rising up off the lake. I binned 3x3 rather than my usual 2x2 in an effort to get enough signal to work with compared to the ice. Oddly, while the fogging was severe it was pretty even with not as much of a gradient problem as I have higher in the sky with less ice to look through. I don't understand it but sure do appreciate it! References I saw say there are HII bubbles all over this guy. But I wasn't able to image but a few in the area to the upper left. Though there are a lot of hints of pink throughout the horizontal arm. This may be noise rather than true signal, I just don't know. I was only able to get 1 frame of color for each color before the fogging go so severe I had to quit (was hitting 40,000 ADU in 10 minutes which puts the fog into my non linear range as well as all the details in the galaxy. That meant my standard galaxy curves wouldn't work and I had to figure out new ones. One color frame isn't enough for something this faint. It took 5 nights to get the data I did then the clouds moved in and have not left since. Due to the intense fogging this is a rather noisy shot. I was going to get more data on it this month but the clouds had other ideas It is now on the way down and will not again be this high in my dark sky until next fall so this will have to do for this year. 14" LX200R @ f/10, L=7x10' RGB=1x10' all binned 3x3, STL-11000XM, Paramount ME Rick |
#4
|
|||
|
|||
ASTRO: IC 1613 another dwarf galaxy
"Rick Johnson" wrote Great image Rick! It's sort of reminiscent of the LMC. I hope that you do get a shot at some more data on this galaxy this year. However, at least you are getting in a little imaging. Over here in NY we've only had a few hours of clear sky for the last 6 weeks or more, and that has all been after midnight under bright moon. It's been the worst December for astronomy in years. George N |
#5
|
|||
|
|||
ASTRO: IC 1613 another dwarf galaxy
George Normandin wrote: "Rick Johnson" wrote Great image Rick! It's sort of reminiscent of the LMC. I hope that you do get a shot at some more data on this galaxy this year. However, at least you are getting in a little imaging. Over here in NY we've only had a few hours of clear sky for the last 6 weeks or more, and that has all been after midnight under bright moon. It's been the worst December for astronomy in years. George N Same here. I took this earlier in the evening of the 9th (UT) same night as LBN826-7. Down low ice got too thick, the second color frames were unusable. I'll have the ice through February and likely into March so no chance for more data on this guy. He's now too low in the SW even without the ice. A big hunk of my to-do list went untouched this fall. Been a horrid fall for imaging. No end in sight either Rick -- Correct domain name is arvig and it is net not com. Prefix is correct. Third character is a zero rather than a capital "Oh". |
#6
|
|||
|
|||
ASTRO: IC 1613 another dwarf galaxy
Nice work Rick! Lots of interesting detail. I had a good day working on
the observatory, it will be dried in tomorrow. I also bought a ST-2000XCM. With my 8" Schmidt-Newtonian it will have a 38.1 X 50.8 arcmin fov with 1.91 arcsec/pix. John N. Gretchen III N5JNG NCS304 http://www.tisd.net/~jng3 |
#7
|
|||
|
|||
ASTRO: IC 1613 another dwarf galaxy
john wrote: Nice work Rick! Lots of interesting detail. I had a good day working on the observatory, it will be dried in tomorrow. I also bought a ST-2000XCM. With my 8" Schmidt-Newtonian it will have a 38.1 X 50.8 arcmin fov with 1.91 arcsec/pix. John N. Gretchen III N5JNG NCS304 http://www.tisd.net/~jng3 They do offer it rather cheap. Pixel size is a good match for your short focal length scope. Thought you might stick with a Starlight camera. Their newer chips seem to be turning out some good work and the one shot is much improved. I've not used the 2000XCM. I'd think it noisier and more in need of a good dark library than the Sony chip you used to use. My set-up will give 0.5" pixels but seeing rarely supports that. I've tried only one full shot at that resolution. http://www.prairieastronomyclub.org/...0RGB2X10C3.jpg At 4008x2672 it is rather large in size and download time. Mostly I work at 1" binned 2x2 though when seeing is lousy or I want more signal I go to 1.5" as in the IC 1613 shot. Those are usually about 1336 pixels wide, the 1" per pixel ones are about 2000 wide. Actually, per my astrometry program, it is 1.003" per pixel but I'm not going to worry about that accuracy! The nice thing about lots of pixels is you can bin and still have a decent size image. Since the chip uses the fully illuminated fov of the scope there's no gain using a compressor. When I was in New Zealand last year there was a old 2001 chip mono version available to me but I spent what little clear time I had viewing all the stuff they have that was new to me. Didn't begin to cover what I'd wanted due to clouds. Seems to be a problem of mine. Sometimes this fall has made me feel like Joe Btfsplk or how ever that vowel free name is spelled. A Al Capp character with a cloud over his head all the time. Rick -- Correct domain name is arvig and it is net not com. Prefix is correct. Third character is a zero rather than a capital "Oh". |
#8
|
|||
|
|||
ASTRO: IC 1613 another dwarf galaxy
Awesome image Rick! This one will have the new chip... will post
finished observatory pics later today Rick Johnson wrote: When I was in New Zealand last year there was a old 2001 chip mono version available to me but I spent what little clear time I had viewing all the stuff they have that was new to me. Didn't begin to cover what I'd wanted due to clouds. Seems to be a problem of mine. Sometimes this fall has made me feel like Joe Btfsplk or how ever that vowel free name is spelled. A Al Capp character with a cloud over his head all the time. Rick -- John N. Gretchen III N5JNG NCS304 http://www.tisd.net/~jng3 |
#9
|
|||
|
|||
ASTRO: IC 1613 another dwarf galaxy
Great image Rick. I also got some frames of IC 1613 last fall, but I think I
didn't get enough data to be worth processing. Stefan "john" schrieb im Newsbeitrag m... Awesome image Rick! This one will have the new chip... will post finished observatory pics later today Rick Johnson wrote: When I was in New Zealand last year there was a old 2001 chip mono version available to me but I spent what little clear time I had viewing all the stuff they have that was new to me. Didn't begin to cover what I'd wanted due to clouds. Seems to be a problem of mine. Sometimes this fall has made me feel like Joe Btfsplk or how ever that vowel free name is spelled. A Al Capp character with a cloud over his head all the time. Rick -- John N. Gretchen III N5JNG NCS304 http://www.tisd.net/~jng3 |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
We are aliens from Sagittarius Dwarf galaxy! | [email protected][_1_] | Astronomy Misc | 0 | June 26th 07 04:55 PM |
Paper: Draco, a flawless dwarf galaxy | Robert Karl Stonjek | Astronomy Misc | 0 | January 24th 07 11:51 PM |
Our galaxy from the Sag. dwarf | John den Haan | Misc | 3 | December 19th 04 03:29 PM |
the Pegasus Dwarf is a satellite of our galaxy? | sheep defender | Astronomy Misc | 16 | October 28th 04 09:52 AM |
Galaxy Anchor Black Holes (GABHs) pop up as Tidal Dwarf Galaxies inside Tidal Galaxy Tails. | Leo | Amateur Astronomy | 0 | October 16th 03 07:00 AM |