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.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"2983 results found.
- GRB 060213: IPN localization
- GRB 060211A: Further refined analysis of the Swift burst
- GRB060105: optical observations
- GRB 060211A: Partial refined analysis on the Swift-BAT burst
- GRB 050826: Optical Afterglow and Host Galaxy
- GRB 060211B: Swift/BAT refined analysis
- GRB060211.7: MASTER_optical_observation under the snow
- GRB 060211B: Swift-BAT detection of a burst
- GRB 060206: Swift/UVOT Observations
- GRB 060206: Swift-BAT refined analysis
- GRB 060204B: Swift-BAT refined analysis
- GRB 060204B: Swift detection of a burst
- GRB 060202: PROMPT Observations
- GRB060202, optical observation
- GRB060114, optical observation
- GRB060110, optical observation
- GRB060108, optical observation
- GRB 051227: Refined analysis of the Swift-BAT burst
- GRB 051221A: RAPTOR Fading Counterpart Constraint
- GRB 051221: IR Observations at GRB+1hr
- GRB 051210: Magellan Imaging
- GRB 051111: ROTSE-III Analysis of Prompt Counterpart
- GRB051109A: further steepening in the X-ray light curve
- GRB051021: A GRB Localized by HETE
- GRB 051008, optical observations
- Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
- GRB050922C - Swift UVOT preliminary analysis
- GRB 050922C: Swift detection of a bright burst
- GRB 050922B: ROTSE-III Optical Limits
- WIRO observations in I of GRB 050908
- GRB050908 : Swift-XRT refined analysis
- GRB 050908: Swift-BAT refined analysis
- GRB 050908: Optical observations
- GRB 050908 : Swift XRT position
- GRB 050908: KAIT observations
- GRB 050908: Optical Observations
- GRB 050904: Swift/UVOT observations
- GRB050827: Swift-BAT detection of a burst
- GRB 050826: Optical Candidate
- GRB050817: Negative Optical Observations
- GRB 050814: Swift XRT Afterglow Localization
- GRB 050814: Swift detection of a burst
- GRB 050813: Swift-BAT refined analysis
- GRB 050813: Swift XRT afterglow localization
- GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
- GRB 050802: early Swift XRT analysis results
- GRB 050730, corrected photometry and break?
- GRB050801: Swift-BAT detection of a burst
- GRB 050730, spectra and optical photometry
- H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
- GRB 050603: Afterglow Identification from LCO
- Swift/BAT Detection of GRB050603
- GRB050528, XRT observations
- GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
- GRB 050505: early time observations
- GRB 050502 - A long GRB detected with INTEGRAL
- GRB 050416,optical observation
- GRB050412: P60 Observations
- GRB 050408: Optical limit
- GRB 050410, optical observations
- GRB 050408, optical observations
- GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
- GRB050331: No Afterglow Detected
- GRB 050331: Swift XRT Position
- GRB050223: analysis of the XMM-Newton observation
- GRB 050219b: candidate NIR afterglow
- GRB050223 XMM-Newton observation
- GRB 050223: Swift XRT Position
- GRB050219b: CORRECTION to time of UVOT observations
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB 050219b: CORRECTION to refined XRT position
- GRB 050219b: Optical and near-IR observations from LCO
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB 050219b: Refined XRT position
- GRB 050219b: CORRECTION: Swift XRT Position
- GRB 050219b: Swift XRT Position
- GRB 050209 Optical observations
- GRB 050209: Optical observation
- GRB 050123: KAIT observations
- Third epoch observations of SGR 1806-20 with VLA
- GRB041224: Swift-BAT detection of a soft burst
- GRB041219: Optical Afterglow Detection
- GRB 041006: GETS Optical Afterglow Observation
- GRB 041006 : optical follow-up observation at Lulin Observatory
- Bursts from SGR 1806-20: Preliminary INTEGRAL results
- Very strong outburst from SGR 1806-20 detected with INTEGRAL
- GRB040924: Optical afterglow properties
- TAROT Observations of GRB 040916 (HETE #3558)
- GRB040912(=H3557): Observations with the Chandra X-ray Observatory
- GRB040912 : Kiso Optical follow-up observation
- GRB 040812: Second epoch CXO Observations
- CXO observation of GRB 040812
- GRB040706:observation at University of Miyazaki
- IPN Summary of SGR1806-20 Activity in 2004
- Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
- GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
- Lulin optical follow-up observations of GRB031026
- XRF 030824: additional observations at CFHT
- IPN triangulation of GRB031007 (two large error boxes)
- IPN triangulation of GRB030922B (large error box)