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"3039 results found.
- 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)
- XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
- IPN triangulation of GRB030919 (large error box)
- GRB030913: AAVSO optical observations
- GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
- IPN triangulation of GRB030714 (two large error boxes)
- IPN triangulation of GRB030626 (two large error boxes)
- GRB030429, refiend optical brightness
- GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
- GRB030429: Optical Observations
- GRB 030329, the review of the sky area in plate archive (1950-1998)
- GRB030329: optical observations at Tokyo Tech
- GRB030329 - near contemporaneous optical limits from CONCAM
- IPN triangulation of GRB030325 (single small error box)
- IPN triangulation of GRB030325 (two small error boxes)
- IPN triangulation of GRB030320 (small error box)
- GRB 030227: Optical limit at RIKEN
- GRB 030228, optical observations
- GRB 030227: fading of candidate optical afterglow 'S1-A'
- GRB 030227, possible optical counterpart of XMM-Newton source
- GRB030227 - faint tentative OT candidate
- GRB 030227: Kyoto optical observation
- IPN triangulation of GRB030119 (two large error boxes)
- IPN triangulation of GRB030117 (two large error boxes)
- IPN triangulation of GRB021219 - CORRECTION
- GRB021219: a long GRB localized by INTEGRAL
- IPN triangulation of GRB021206 (small error box)
- GRB021104: Optical Observations
- IPN triangulation of GRB021020 (smaller error box)
- GRB021016(=H2397): A Long GRB Localized by HETE
- IPN triangulation of GRB021008 (two small error boxes)
- GRB 021004: Optical measurement at OHP
- GRB 021004: Optical Photometry at 2.5 Days
- GRB021004: Update Bisei photometric data
- IPN triangulation of GRB020914
- Confirmation of IPN error box for GRB020910
- IPN triangulation of GRB020910
- Single IPN error box for GRB020904
- IPN triangulation of GRB020904
- GRB 020812: optical observation at Kyoto University
- GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
- GRB020812: optical observations
- IPN triangulation of GRB020708
- IPN triangulation of GRB020708
- GRB 020705: Optical observations