Sky this Week » Galaxy cluster

NGC 51 galaxy group

Vern — Sun, 26 Nov 2006 04:23:07 +0000

Located in the constellation Andromeda is a sextet of faint galaxies (NGC 48, 49, 51 and IC 1534, 1535 and 1536). Estimated distance is 300 million light years. NGC 51 is the brightest of the group at vmag 14.1

Image taken from Louisville, CO at 21:31 to 21:46 MST with Celestron Nexstar11 telescope, Meade F3.3 focal reducer, and Stellacam II video camera. SCII set at 9/14 gain, no gamma, and integrate 256 frames (8 sec). Dark subtracted and flat field corrected with ImagePlus, aligned and stacked with Registax4. Sky was mostly clear, temperature 40 °F, no wind, transparency very good, and turbulence 5/10.

Stephan’s Quintet (Arp 319)

Vern — Tue, 03 Oct 2006 02:40:15 +0000

Stephan’s quintet (NGC 7317, 7318A, 7281B, 7319, and 7320) in the constellation Pegasus is a grouping of 5 galaxies in a 3.5 arc-min area. The largest and brightest of the group, NGC 7320, is located in the lower left of center. Due to difference in red shift, the conventional view is that NGC 7320 is not part of the other 4 galaxies in the group. It is instead actually part the nearby NGC 7331 group. However there is evidence of a connecting tail extending from 7320 which implies interaction with the the other galaxies. Some astronomers, such as Halton Arp, maintain that because of this the current beliefs about red shift should be re-examined.

The galaxies 7318A and B located near the center of the image are quite interesting as well. Not only are they interacting but they also have differing red-shifts. Galaxy 7318B is currently moving toward the others at high speed setting up a tremendous shock wave larger than our own milky way galaxy in size.

Location was Crow Valley Campground in the Pawnee Grasslands just north of Briggsdale, CO. Temperature was 44°F and humidity was 56%. The sky was mostly clear with a few thin clouds, no wind, turbulence around 6/10, and transparency varied from good to very good. Fifteen minutes of video taken with Celestron Nexstar11 telescope, APT wedge, Meade F3.3 focal reducer, and a Astrovid Stellacam II video camera. Camera set at 9/14 gain, integrate 256 (8 sec), and medium gamma. Images were dark subtracted and flat field corrected with ImagePlus, aligned and stacked with Registax3.

NGC 7463, NGC 7464, and NGC 7465

Vern — Sun, 03 Sep 2006 21:04:04 +0000

About a degree north and west of the brightest star in Pegasus, Markab, is a nice galaxy triplet of NGC 7463, 7464, and 7465. NGC 7465 appears to be the brightest of the three and has a bright central core.

Celestron Nexstar11, Meade F3.3 focal reducer, and Astrovid Stellacam II was used to take the image from Louisville, CO on Sept 3, 2006 around 05:57 UT (just before midnight Sept 2). Temperature was 42°F, 77% humidity, sky was clear, transparency was good, and turbulence about 5/10.

Hickson 79 (NGC 6027 and NGC 6027A – E)

Vern — Wed, 28 Jun 2006 20:13:54 +0000

Seyfert’s Sextet (Hickson 79) located in the constellation Serpens is one of the densest known galaxy groups. Four of the galaxies are believed to be interacting (NGC 6027, and NGC 6027a-c). Component “d” is not part of a group, it is further distant and just happens to be in line of sight. Component “e” is thought to be a tidal tail thrown out from gravitational interaction.

Images taken from Louisville, CO June 26, 2006 at 11:59 MDT with Celestron Nexstar11, F3.3 focal reducer, and Astrovid Stellacam II video camera. Camera settings: integrate 128, gain 9/14, medium gamma. Images were dark subtracted, flat field and bias corrected with ImagePlus. Aligned and stacked 150 images with Registax3. Brightness enhanced with ImagePlus, cropped with Photoshop Elements. Sky was clear, temperature 57°F, transparency very good, turbulence 6/10.

NGC 5171

Vern — Fri, 02 Jun 2006 22:07:21 +0000

I recently received the “Galaxy Groups and Clusters” book from the Astroleague and decided to try imaging some of the listed objects. Below is an image of NGC 5171 in constellation Virgo. There are at least 9, probably more galaxies shown in the image which I’ve identified 7.

Location Louisville, CO, time 11:45 to 0:015 MDT. Weather clear, temperature 57°F, humidty 60%, no wind, clear sky, transparency very good, turbulence good (6/10). Equipment used was a Celestron Nexstar11, Meade F3.3 focal reducer, and Astrovid Stellacam II video camera. Integration at 256, gamma at medium and gain at 9/14. Fifteen minutes of video was dark subtracted, flat field and bias corrected. Aligned and stacked with Registax3, brightness enhanced with ImagePlus, cropped and labeled with Photoshop Elements2.

Copeland’s septet (Hickson 57)

Vern — Thu, 20 Apr 2006 22:37:58 +0000

Contained in about 6 arc-minute area are seven galaxies to challenge those with large aperature scopes and dark skies (or Stellacams from light polluted backyards). I didn’t have the gamma set correctly set on the Stellacam when I took these. I’m learning that the gamma setting needs to be on medium for faint objects — if it is off there is not much to stack. There should be more detail, I’m going to visit this object again soon. Image taken last evening, April 20 just after midnignt with Nexstar11 telescope, Meade F3.3 focal reducer, and Stellacam2 video camera, gain 9/14, gamma off (unfortuantely), and integrate at 256.