GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
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subject:"Swift"body:"GRB"submitter:"Judith Racusin"3400 results found.
- XRF050509C: Chandra Afterglow Detection
- XRF 050509c: Swift XRT Upper Limit
- GRB 050520: P200 Observations
- GRB 050504: Swift XRT afterglow candidate has faded
- Refined Chandra analysis of GRB 050509b
- Chandra observation of GRB 050509b
- GRB 050502a: Swift XRT Upper Limit
- GRB (?) 050504: IR Observations, Intriguing Source
- GRB 050502: Confirmed variability of the afterglow candidate +
- GRB 050421: Further Analysis of IR imaging
- GRB 050421: IR Observations
- GRB050326: analysis of the XMM-Newton observation
- GRB050416B: IR observations
- GRB050416: P200 NIR Observations
- GRB 050408: Swift XRT measurement of possible jet break
- GRB 050408: Swift XRT analysis
- GRB050408: REM NIR and Optical observation
- GRB 050326 XMM-Newton observation
- GRB050223: analysis of the XMM-Newton observation
- Swift-BAT trigger 107873: No Swift XRT counterpart
- Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
- GRB 050306: REM optical-infrared observations
- GRB 050126: Confirmation of the NIR afterglow candidate
- GRB 050219b: candidate NIR afterglow
- GRB 050219b: Optical and near-IR observations from LCO
- GRB 050126: Detection of NIR afterglow with Keck/NIRC
- GRB 050124: NIR afterglow confirmed with Keck/NIRC
- GRB 050124: NIR Candidates from Keck/NIRC
- GRB050117: Palomar WIRC Ks-band observations
- NIR Observations of GRB 041219
- GRB 041211: Infrared Observations
- GRB041015: Near-Infrared observations
- GRB041006: Near Infrared observations
- GRB040827: analysis of the XMM-Newton observation
- GRB 040827: 2nd epoch of Magellan K-band imaging
- GRB 040827: Detection of NIR afterglow
- GRB 040812: Second epoch CXO Observations
- CXO observation of GRB 040812
- GRB 040730, infrared observations
- SGR 1806-20: no IR variability of the proposed counterparts
- SGR 1806-20, potential NIR counterpart
- GRB 040511: NIR observations with REM
- IBAS GRB alerts 1739, 1740, 1741
- GRB040223: Deep NIR NTT data re-analysis
- GRB 040223: Deep NIR NTT observations
- GRB 040223: REM IJK Observations
- GRB 040223 XMM-Newton observation ...
- GRB 031203 XMM-Newton observation
- GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
- XMM-Newton Observation of GRB031203
- GRB 031203: Deep NIR NTT & VLT observations
- XMM-Newton Observation of GRB031203
- GRB 031203: IR NTTobservations do not confirm REM detection
- GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
- GRB 031203: IR REM Observations
- GRB 031203 XMM-Newton observation
- XRF030723: Palomar observations and proposed counterpart
- GRB030329: second XMM-Newton observation
- GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
- GRB 030528: Infrared Observations and the Proposed IR Counterpart
- GRB 030528: tentative NIR counterpart
- GRB 030329: Optical limit (contemporaneous photography)
- GRB 030429: IR photometry with IRSF/SIRIUS
- GRB030501: TAROT candidate afterglow present in archival images
- GRB 030429: confirmation of afterglow candidate
- GRB030418: Kiso near infrared observations
- GRB030329: Near Infrared Observations at Gunma
- GRB 030329: fading X-ray afterglow with RXTE
- XMM-Newton observation of GRB030227
- GRB 030115: Further IR observations with IRSF/SIRIUS
- GRB 030115: IR observations with IRSF/SIRIUS
- GRB 021201, optical observations
- GRB 021201 (short/hard), NOT observations
- Chandra observation of the IPN error box of GRB021201 (short/hard)
- Detection of activity from SGR 1900+14 with the RXTE/PCA
- GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
- GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
- SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
- SGR-like Bursts from the AXP 1E 2259+586
- GRB 020418, optical/near-IR observations
- GRB020531, optical observations
- XRF020427: Chandra Observations and Candidate X-ray Counterparts
- GRB 020321: Candidate X-ray Counterparts
- GRB 020331: Candidate Optical Afterglow
- GRB 020331: NIR Observations
- GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
- VLT observations of GRB 020124: The fading optical/near-infrared afterglow
- GRB 011121: NIR observations, host galaxy?
- GRB 011121: Detection of Bright IR Counterpart
- SGR 1900+14 : RXTE observations
- GRB 001204: Ks observations
- GRB 001212 possible OA in 2MASS
- GRB 001109: deep JHK upper limits
- The Likely Optical/Infrared Afterglow of GRB 001011
- SGR 1806-20 burst activity
- GRB 000418: Detection of the Host Galaxy
- X-ray Afterglow of GRB 000529
- IR observations of GRB991216
- BeppoSAX NFI Observation of GRB991106
- GRB980703: Radio transient