Archive

Previous Response

TITLE: GCN CIRCULAR
NUMBER: 6084
SUBJECT: GRB 070208: RAPTOR detection of early afterglow onset
DATE: 07/02/08 23:35:08 GMT
FROM: James Wren at LANL <jwren@nis.lanl.gov>

J. Wren, W.T. Vestrand, P.R. Wozniak, R. White, J. Pergande of Los Alamos National Laboratory report:
 

Our Raptor-S telescope responded to Swift trigger 259714 (Sato et al., GCN 6074) at 09:11:17.10 UT, 42.8 s after the trigger and 6.3 s after receiving the GCN packet. We clearly detect the source at the location of the optical counterpart identified by Guidorzi et al. (GCN 6077). Our first 5 second exposure was obtained while the Swift BAT was still detecting emission from the second GRB pulse (Markwardt et al., GCN 6081).
Our measurements show that the optical counterpart brightened from fainter than magnitude 18.7 to 18.2 in the first 300 seconds after the trigger time and then began to fade steadily after that. Our unfiltered magnitudes were calibrated using the R-band magnitudes from the USNO B1.0 catalog.

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5539
SUBJECT: GRB 060906: Early RAPTOR optical limits
DATE: 06/09/06 22:01:25 GMT
FROM: James Wren at LANL <jwren@nis.lanl.gov>

J. Wren, W.T. Vestrand, P.R. Wozniak, R. White, S. Evans, and J. Pergande of Los Alamos National Laboratory report:

The RAPTOR array of telescopes autonomously responded to Swift trigger 228316. Conditions were cloudy at our primary telescope site but our wide-field RAPTOR-B small telescope array, located at our secondary site, imaged the event under clear conditions.
Imaging began at 08:34:12.53 UTC (86.0 s after the trigger, 5.8 s after receipt). We do not detect the counterpart seen by the Swift XRT (Racusin et al. GCN 5528) and P60 (Cenko et al. GCN 5529).
The initial unfiltered 5 s exposure yields a 3-sigma limiting magnitude at the counterpart location of R=15.2 when calibrated against the GSC 1.1 R-band. This limit has not been corrected for foreground galactic extinction.

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 4687
SUBJECT: GRB 060206: RAPTOR observations of afterglow candidate variability.
DATE: 06/02/06 08:55:58 GMT
FROM: Przemyslaw R. Wozniak at LANL <wozniak@lanl.gov>

P.R. Wozniak, W.T. Vestrand, J. Wren, R. White, and S. Evans at Los Alamos National Laboratory on behalf of the RAPTOR team report:

RAPTOR's autonomous system for locating optical counterparts to GRBs identified a variable object at position RA=202.931, DEC=35.0509 deg.
At 2900 seconds after the trigger RAPTOR measured an R-band magnitude of ~17.3, followed by a brightening to ~16.3 mag over the next 700 seconds, where it remained for about 200 seconds before fading to ~16.9 mag over the next 45 min. The real time position was reported only to the RAPTOR rapid response team because of unusual photometric behavior of the object.
This variable source has a location consistent with the position of the optical afterglow candidate found by Fynbo et al. (GCN 4683) and confirmed by Boyd et al. (GCN 4684).

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 4474
SUBJECT: GRB 060110a: RAPTOR detection of early optical emission.
DATE: 06/01/10 19:55:23 GMT
FROM: Przemyslaw R. Wozniak at LANL <wozniak@lanl.gov>

P.R. Wozniak, W.T. Vestrand, J. Wren, R. White, S. Evans of Los Alamos National Laboratory report:

Our autonomous Raptor-S telescope responded to Swift trigger
176702 (Zane et al. GCN 4463) at 08:01:42.42 UT (6.8 seconds after receiving the trigger). We clearly detect a fading optical source at the location of the IR counterpart identified by Bloom et al.
(GCN 4471). The measurements show that the optical counterpart faded from magnitude R=16.1+/-0.1 (5-second exposure) to about 17.5 over the first ten minutes. Our unfiltered magnitudes were calibrated using R2 magnitudes of the field sources in USNO B1.0 catalog.
 

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 4380
SUBJECT: GRB 051221A: RAPTOR Fading Counterpart Constraint
DATE: 05/12/22 02:54:22 GMT
FROM: James Wren at LANL <jwren@nis.lanl.gov>

J. Wren, W.T. Vestrand, R. White, P. Wozniak, and S. Evans report on behalf of the RAPTOR team at Los Alamos National Laboratory:

Starting at 02:57:05 UT (1.1 hours after the burst), the RAPTOR-S telescope began a manually initiated response to the short burst identified by Swift (Parsons et al. 4363). Within the XRT error circle (Burrows et al. 4366) at a position consistent with the location of the candidate J-band infrared (Bloom, GCN 4368) and R-band optical (Berger, GCN 4369) counterparts, a stack of 20 30-second unfiltered RAPTOR images yields a marginal detection of a source. Using the USNO-B1 catalog for calibration and ignoring any extinction along the line of sight, our derived 5-sigma upper limit on the brightness of an optical counterpart at that epoch (1.3 hours after the trigger) is R=20.2+/-0.2 magnitude.

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 4239
SUBJECT: Early RAPTOR measurements of GRB 051109a - the movie.
DATE: 05/11/10 00:37:54 GMT
FROM: Przemyslaw R. Wozniak at LANL <wozniak@lanl.gov>

P.R. Wozniak, W.T. Vestrand, J. Wren, R. White, S. Evans on behalf of the RAPTOR team report:

Starting at 01:12:54.42 UT on November 9, 33.9 seconds after the Swift BAT trigger, the Raptor-S robotic telescope at Los Alamos National Laboratory responded to Swift trigger 163136 (Tagliaferri et al., GCN 4213). The automated response was composed of a series of ten 5-second duration exposures followed by 20 10-second exposures and finally by 183 30-second exposures.
The unfiltered images show an optical transient at the position identifed by Rykoff et al. (GCN 4211) that fades from magnitude R ~15.1 to ~17.5 over the course of 20 minutes. The unfiltered magnitudes were transformed to the R2 magnitude scale of the USNO B1.0 catalog.

See Movie

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 3836
SUBJECT: GRB 050820: Early RAPTOR detections
DATE: 05/08/20 18:49:51 GMT
FROM: James Wren at LANL <jwren@nis.lanl.gov>

J. Wren, W. T. Vestrand, P. Woznaik, S. Evans, R. White report on behalf of the RAPTOR team at Los Alamos National Laboratory:

The RAPTOR system of robotic telescopes responded to GRB 050820 (Swift trigger 151207) beginning at 06:35:20.46 UT, 5.5 seconds after the GCN notice was sent. We detect the object reported by Fox and Cenko (GCN 3029). Our early images show the source rising rapidly to a unfiltered peak magnitude of ~14.5. We confirm the Fox and Cenko observation that the source reaches a peak brightness approximately 8 minutes after the burst and then begins a steady power law decline.

GCN GRB OBSERVATION REPORT
NUMBER: 3604
SUBJECT: GRB 050713A: RAPTOR detection of early optical emission
DATE: 05/07/13 23:15:38 GMT
FROM: James Wren at LANL <jwren@nis.lanl.gov>

J. Wren, W.T. Vestrand, P. Wozniak, R. White, S. Evans report on behalf of the RAPTOR team.

The RAPTOR-S telescope at Los Alamos National Laboratory began imaging the field of GRB 050713A (Swift trigger 145675) 22.4 seconds after the GRB trigger -- before the end of the interval of prompt gamma-ray emission (Falcone et al. GCN circ 3581).
At the location of the fading optical and NIR counterpart identified in later images by Malesani et al. (GCN circ 3582) and Hearty et al.
(GCN circ 3583), respectively, we detected a transient optical counterpart. In a stack of eight 10 second unfiltered images starting at 04:29:24.8 UT (with midpoint at 99.3 s after the GRB trigger), we measured the optical transient to have a R-band magnitude of 18.4 (+/- 0.18). Our preliminary transformation to R-band magnitudes was based on field stars from the USNO-B1 catalog.
 

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 3414
SUBJECT: GRB 050509b: RAPTOR deep, early limits.
DATE: 05/05/11 22:18:35 GMT
FROM: Przemyslaw R. Wozniak at LANL <wozniak@lanl.gov>

P. Wozniak, W.T. Vestrand, J. Wren, S. Evans, and R. White, on behalf the RAPTOR team at Los Alamos National Laboratory


The RAPTOR-S telescope at Los Alamos National Laboratory responded to Swift trigger 118749 (Hurkett et al. GCN 3381) and collected a series of
113 unfiltered images starting at 26.57 s and continuing for the first 90 minutes after the trigger. The exposure durations are 10 s for the first 10 images, 30 s for the next 10 images and 60 s for the remaining
93 images.

Using difference imaging techniques, comparing individual images as well as stacks of images, we have placed limits on early time variability at the locations of sources S1-S4 (Cenko et al. GCN 3401) within the XRT error circle (Rol et al. GCN 3395). We find no evidence for transient emission at the four candidate locations with the following 5 sigma limits.
 

Further Analysis

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 3085
SUBJECT: GRB 050309, Early optical limits from RAPTOR
DATE: 05/03/11 00:57:16 GMT
FROM: Przemyslaw R. Wozniak at LANL <wozniak@lanl.gov>

P.R. Wozniak, S. Evans, W.T. Vestrand, R. White, J. Wren (LANL) on behalf of the RAPTOR team.

The RAPTOR A telescope responded to Swift-BAT trigger 107873 and began optical imaging of the burst location in 6.7 seconds from the time of receiving the alert (2.3 min. after GRB time). Photometry at the locations of the two X-ray candidate counterparts to GRB 050309 reported by Barthelmy et al. (GCN 3082) shows no optical emission in a series of 10 second exposures, each with the limiting magnitude R=15.0. A stack of the first 10 images with the mean time of observation 4.2 min. after the GRB time had a magnitude limit of R=16.1.
 

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 2889
SUBJECT: Deep RAPTOR observations during GRB 041219
DATE: 04/12/20 20:11:31 GMT
FROM: James Wren at LANL <jwren@nis.lanl.gov>

J. Wren, W. T. Vestrand, S. Evans, R. White, and P. Wozniak report on behalf of the RAPTOR team at Los Alamos National Lab.

The RAPTOR-S telescope responded robotically to INTEGRAL trigger #2073. Our first image began at 01:44:13.65 UT, 8 seconds after receipt of the Integral notice and while the GRB was still ongoing.
Summing our images over the duration of the GRB emission (1:44 UT to
1:52 UT), we marginally detect a possible source very close to our threshold at the location of the candidate given by Blake and Bloom (GCN 2870). Interpreted as an upper limit, these observations indicate the prompt optical emission remained fainter than R=19.4.
 

More Information....details on GRB041219
 

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 2847
SUBJECT: GRB041211: RAPTOR observations
DATE: 04/12/15 18:16:58 GMT
FROM: Przemyslaw R. Wozniak at LANL <wozniak@lanl.gov>

P. Wozniak, J. Wren, W.T. Vestrand, and R. White, report on behalf of the RAPTOR team.

Stereoscopic observations collected by the RAPTOR wide-field sky monitoring systems allow us to place optical limits on a prompt optical flash from GRB 041211 (HETE trigger 3622). Five seconds after receiving the initial HETE type 40 trigger, we began tiling around the nominal HETE pointing direction. Our first image containing the GRB location began at 11:34:09.93 UT (T+143.02s). This image was 10 seconds in duration and reached an unfiltered limiting magnitude of 11.5. No new object was detected within the error circle based on comparison to DSS image. Later images reaching 15th magnitude also showed no new objects compared to DSS images.
 

Images (from Testing phase)