GCN Circular 3916
Subject
GRB050904: Optical Observations
Date
2005-09-04T16:19:06Z (19 years ago)
From
Aaron Price at AAVSO <aaronp@aavso.org>
Dr. D.T. Durig (Cordell-Lorenz Observatory, University of the South),
Dennis Hohman (Stone Edge Observatory) and Aaron Price report on behalf of
the AAVSO International High Energy Network on observations of the field
of GRB050409 (GCN 3910; Cummings et al.).
Durig does not detect any afterglow with SNR>3 on unfiltered images
centered at 08:30:59 UT. However, sources do exist with an SNR=3 at
locations near that reported in GCN #3913 (Haislip et al.). Locations and
magnitude:
00 54 51.38 14 04 48.9 20.0 mag
00 54 50.42 14 05 30.6 20.1 mag
00 54 51.55 14 05 28.8 20.2 mag
Full details, including a link to the FITS image is available at the
bottom of this notice.
Also, Hohman observed the field with an Rc filter centered on 06:18 UT
and does not report any afterglow to Rc=18.6. Details on his observation
are also below.
The AAVSO thanks the Curry Foundataion for their continued
support of the AVSO International High Energy Network.
Report filed on Sun Sep 4 07:54:36 2005:
Name: Dr. D. T. Durig
email: ddurig@sewanee.edu
Observer: D. T. Durig, A. P. Long, A. L. Yacko, J. L. Rouquette, J. C.
Heiss
Site: Cotrdell-Lorenz Observatory
Location: Sewanee, Tenn, USA
LatitudeLongitude: 35 12 N 85 55 W
Elevation: 600m
Scope: SCT 0.30 m
ScopeFocalRatio: f/5.9 1760 mm
CCDVendor: SBIG STL-1001E
CCDDetector: KAF-1001E
CCDSize: 1024x1024
CCDPixelScale: 2.8
CCDFOV: 48x48 full, 12x12 quater shown
Object: GRB050904
ObsDate: 2005 Sept 4
ObsMidPointTime: 08 30 59 UT
TimePerFrame: 300 sec
NumberOfFrames: 37
Filters: CR
Processing: dark, flat, register, add, 1/4 frame crop
Seeing: ~6
LimitingMag: approx. 20.5
Sky: clear but windy
afterglowmag: NA
afterglowerr: NA
compstars: 850 USNO B1.0 in Full Frame
Report: Total exposure 185 minutes (37x300 sec= 11,100 sec ). I see no
afterglow at the reported position(s) above my detection limit but there
appears to be three very dim diffuse sources nearby at
00 54 51.38 14 04 48.9 20.0 mag
00 54 50.42 14 05 30.6 20.1 mag
00 54 51.55 14 05 28.8 20.2 mag
All three are near my limiting mag with sigma equal to 3.
In the noise I measure
00 54 49.69 14 05 08.5 21.9 mag
but with sigma equal to 1.5 and below my detection limit of 20.5 mag.
A FITS image has been uploaded to
ftp://ftp.aavso.org/grb/Dr.D.T.Durig_GRB050904_2453617.99625_.fits
--------------------
Report filed on Sun Sep 4 03:36:21 2005:
Name: Dennis Hohman
email: dennishohman@adelphia.net
Observer: Dennis Hohman HDF
Site: Stone Edge Observatory
Location: Orchard Park, NY USA
LatitudeLongitude: -78 45, 42 46
Elevation: 290M
Scope: C8 200mm
ScopeFocalRatio: 1200
CCDVendor: ST7XME
CCDDetector: KAF402E
CCDSize:
CCDPixelScale: 1.55
CCDFOV: 19x13
Object: GRB050904
ObsDate: 09/04/05
ObsMidPointTime: 06:18
TimePerFrame: 240 sec
NumberOfFrames: 8
Filters: R
Processing: Darks,Flats, bias, coadd
Seeing: 4
LimitingMag: 18.6
Sky: mostly clear with occasional patchy clouds
afterglowmag:
afterglowerr:
compstars:
Report: Full error circle covered. No new object observed to a limiting
magnitude of 18.6 based USNO A2.0 catalog
comments:
A FITS image has been uploaded to
ftp://ftp.aavso.org/grb/DennisHohman_GRB050904_2453617.81691_.fits