NGC 7753 - Arp 86
Object: NGC 7753; SAB(rs)bc galaxy in Pegasus 12.1m, 3.3'x2.1' and companion NGC 7752; Irregular 14.1m, 0.8'x0.5'.
Subimages: 3x 1200s (1 hr) SD Maskcombined after bias and dark calibration.
FWHM 2.8" - 4" across the field, collimation problem.
Scope: C11XLT with RLS65 reducer, EFL=1981mm (f/7 effective)
Mount: Losmandy G11 with Gemini L4
Camera: ST7EI (0.94"/pixel) set to -25C oriented at 0d23'(N up, E left)
Guiding: SX716 camera on a Taurus Tracker III OAG. Exposure time 4 sec.
Acquisition and Processing: MaxIm DL/CCD v4.5
Imaged on: Sept 29, 2006
L-R deconvolution: noise and bgd=auto, PSF radius=1,2, Iterations=10. FWHM went from 3.1" to 2.8"
DDP: bgd=1580, mid=2600, filter=none
Crop: remove some ugly looking stars near the edges.
This is an interacting pair of galaxies at about 272 Mly, similar to M51 but 5 times further away. The smaller companion is an extremely active galaxy (a so called starburst galaxy), one of the most active among interacting pairs. I will have to revisit this object with better seeing and more exposure time.
Version without LR deconvolution
While aligning the frames I noticed a weird streak, that moved from frame to frame.
I made an AVI out of it.
MPChecker returned the following object, brighter than magnitude 20.0, in
the 15.0 arcminute region around R.A. = 23 47 10, Decl. = +29 28 46 (J2000.0) on 2006 09 30.31 UT:
|Object||R.A.||DEC||Vmag||RA rate ("/hr)||DEC rate ("/hr)|
|2002 XA12||23 47 16.1||+29 27 10||18.1||27-||17-|
After doing a pinpoint solve and putting the mouse cursor at the head of the streak on the first image I get:
RA = 23 47 16.02 DEC = +29 27 09.4
The object drifts about 0.5' over the one hour exposure. I had earlier estimated the object to be magnitude 18.6 using the MaxIm info window calibrated on the 14.5m USNO2.0 star nearby. So I think I can safely state this is a positive ID of asteroid 2002 XA12.