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.
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"
24051 results found.
- GRB 021004: Additional V-band Polarimetric Observations
- GRB 021004: V-band Polarimetric Observations
- GRB 021004: Optical observations at RIKEN
- GRB 021004, SPM optical observations
- GRB021004: optical observations at Nyrola
- GRB021004: Optical Afterglow
- GRB 020903: Optical observations at RIKEN
- XRF 020903: Supernova
- IPN triangulation of GRB020914
- GRB020903(=H2314): An X-Ray Flash Localized by HETE
- INTEGRAL GRBs added to GCN
- GRB020812: optical observation
- Second epoch K band imaging of GRB 020819
- K band observation of GRB 020819
- HETE 2275: Optical observations
- Polarimetry of GRB020813: evidence for variability
- GRB020812: optical observations
- GRB020813: Early Time Magnitude
- GRB020813, optical observations
- Early Time Limits for GRB020813
- GRB 020813 Afterglow Observations; Possible break
- GRB 020813 multiband optical observations
- GRB020813: optical afterglow
- GRB020813: Fading of Candidate OT
- GRB020813: Candidate Optical Afterglow
- GRB 020812 optical observation
- GRB020801, optical afterglow candidate
- GRB020625 (=H2081): A Long Burst Localized by HETE
- HETE #2081: Optical observations
- GRB 020531, simultaneous optical observations
- GRB020321 : Optical observations.
- GRB 020410, optical observations
- GRB 020331: Candidate Optical Afterglow
- GRB 020322: BeppoSAX observations of the X-ray afterglow
- SN 2002ap - peak brightness date (SN/GRB?)
- GRB020321: a faint BeppoSAX detection
- GRB020317, optical observations
- GRB020305, optical observations
- GRB020124, optical observations
- HETE 1896: Optical observations
- GRB011130 (=XRF011130), Optical Observations
- GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
- GRB 011030: K-band observations
- The X-ray Flash 011030 ('GRB 011030')
- GRB 011019 optical observation
- Optical observation of SGR 1806-20 at the 6-m SAO telescope
- GRB 010921: The afterglow of HETE #1761
- Optical Observations of the field of HETE trigger #1793/GRB 011012?
- Optical Observations of the field of HETE trigger #1793/GRB 011012?
- GRB010921 Optical Observations
- HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
- HETE Trigger #1760 (GRB 010920B?): a new optical source
- HETE Trigger #1759 (GRB 010920?) optical observations
- BeppoSAX/GRBM detection of GRB 010801
- GCN and HETE status
- Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
- GRB 010629 Optical Observations
- IPN triangulation of GRB010613
- IPN triangulation of GRB010612
- GRB010518: a faint BeppoSAX detection
- GRB010324: BeppoSAX/GRBM data
- GRB 010214: X-Ray afterglow
- GRB010213, optical observations
- GRB010126: CONCAM crude optical limits during GRB
- HETE positions added to GCN
- CONCAM null result on GRB001005
- CONCAM crude optical limits before and after GRB000926
- GRB000607, optical observations
- GRB 000615: NIR observations
- IPN triangulation of GRB000519
- RXTE/ASM and IPN localization of GRB 000508B
- BeppoSAX GRB000424
- BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
- GRB000408, lotis optical observations
- GRB 000313 - optical transient in the BATSE error box
- GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
- BATSE GRB trigger criterion changed
- GRB000210 X-ray afterglow
- GRB 000210: BATSE Observations
- GRB000201 Optical Observations
- GRB 000201: TAROT optical observations
- BATSE GRB trigger criteria changed
- BATSE+IPN location of GRB000131
- BATSE location of GRB000126
- BATSE Observations of GRB000115
- Second RXTE Observation of GRB 000115
- Single IPN error box for GRB991229
- GRB 991216: Updated BATSE parameters
- GRB 991216--Summary of RXTE Observations
- GRB 991216: Extremely bright BATSE burst
- GRB991106: BeppoSAX/BATSE results
- BeppoSAX NFI Observation of GRB991106
- GRB 991105: BATSE Observations
- GRB991106, optical observation at SAO-RAS
- GRB 991106, LOTIS Optical Observations
- GRB991105: SAX-GRBM/-WFC detection
- BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
- GRB ALERT: GRB991105
- GRB 991014 - BeppoSAX NFI observations
- GRB991014 BATSE Observations