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"26228 results found.
- GRB 091104: Swift-BAT refined analysis
- GRB 091104: Swift XRT Refined Analysis
- GRB 091104: Swift/UVOT Upper Limits
- GRB 091104: Swift detection of a burst
- Fermi LAT Upper Limits on GRB 091010
- GRB 091102A: Fermi GBM observation
- GRB 091102: Swift-XRT refined analysis
- GRB 091102: Swift/UVOT Upper Limits
- GRB 091102: GROND Upper Limits
- GRB 091102: Swift-BAT refined analysis
- GRB 091102: ROTSE-III Optical Limits
- GRB 091102: Swift/UVOT Finding Chart Observation
- GRB 091102: Swift detection of a burst
- GRB 091031: Fermi GBM detection
- GRB 091024: Fermi LAT upper limits
- GRB 091018: Skynet/PROMPT Observations of Possible Host Galaxy
- GRB 090920: Skynet/DSO Detection
- GRB091029: Swift/UVOT observations
- GRB 091029: Skynet/PROMPT Continued Observations of Fading
- GRB 091029: Swift XRT refined analysis
- Fermi Gamma-ray Burst Monitor trigger 091028818 is not a GRB
- GRB 091029: Swift-BAT refined analysis
- GRB 091029: Gemini-South Redshift
- GRB 091029: Skynet/PROMPT Observations of Peak and Fading
- GRB 091029: GROND Detection of the Optical/NIR Afterglow
- GRB 091029: Swift detection of a burst with an optical counterpart
- GRB 091020: Fermi GBM observation
- GRB 091026: Suzaku WAM observation of the prompt emission
- GRB 091024: YNAO-GMG observations
- GRB 091026: GROND Upper Limits
- GRB 091026: Swift-BAT refined analysis
- GRB 091026: Swift/UVOT Upper Limits
- GRB 091026: Swift-XRT refined analysis
- Konus-Wind and Konus-RF observations of GRB 091024
- GRB 091026: Swift detection of a Gamma Ray Burst
- GRB 091020 : Xinglong TNT upper limit
- Swift-BAT Triggers 373776-373778 are not real
- GRB091024 Swift/UVOT Upper Limits
- GRB 091024: KAIT optical afterglow observations
- GRB 091024: Super-LOTIS early observations
- GRB091024: VRcIc Afterglow Observations
- GRB 091024: Swift-BAT refined analysis
- Swift-BAT Triggers 373679-373684 are not real
- GRB 091024: Fermi GBM Observations
- GRB 091024: Swift-XRT team refined analysis
- Swift-BAT trigger 373691 is a galactic bulge transient
- GRB 091024: Xinglong TNT optical observation
- GRB 091024 : Faulkes Telescope North - Afterglow Confirmation
- GRB 091024: Faulkes Telescope North Afterglow Candidate
- GRB 091024: Swift detection of a burst
- GRB 091018: Skynet/PROMPT Continued Observations of Fading
- GRB 091020: Swift-XRT refined analysis
- GRB 091018: Swift XRT refined analysis
- GRB091020 Swift/UVOT observations
- GRB 091020, Swift-BAT refined analysis
- GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
- GRB 091020: Swift detection of a burst with an optical afterglow
- GRB 091018: Skynet/PROMPT Observations of Fading
- Konus-RF observation of GRB 091018
- GRB 091018 : Faulkes Telescope South Observations
- GRB091018: Swift/UVOT observations
- GRB 091018: Swift-BAT refined analysis
- GRB091018: Magellan Echellette Observations
- GRB 091018: ROTSE-III Detection of Optical Counterpart
- GRB 091015: Skynet/PROMPT Observations
- GRB 091018: Swift detection of a burst with optical afterglow
- GRB 090815: a faint long GRB localized by INTEGRAL
- GRB 091010: Suzaku WAM observation of the prompt emission
- GRB 091010: Fermi GBM observation
- GRB 090531A: Skynet/PROMPT Observations
- GRB 090530A: Skynet/DSO Detections
- GRB 091010: RXTE detection
- GRB 091010 optical upper limits
- Detection of a short GRB 090929A by RT-2 Experiment
- RT-2 observation of the bright GRB 090926A
- GRB 091010: Swift-XRT position
- SuperAGILE GRB is 091010 and not 090910
- GRB 090926A: Skynet/PROMPT Observations of Day 6 - 11 Fading
- GRB 090518: Skynet/PROMPT Observations
- Short-Duration GRB 090621: Skynet/Dolomiti Observations
- GRB 090904A: afterglow confirmation
- GRB 090812: Skynet/PROMPT and GORT Observations
- GRB 091003A: Suzaku WAM observation of the prompt emission
- GRB 090926B: Skynet/PROMPT Observations
- Konus-Wind observation of GRB 091003A
- GRB 090929B: Suzaku WAM observation of the prompt emission
- GRB 090929A: Suzaku WAM observation of the prompt emission
- GRB 091003: Swift-XRT confirmation of fading afterglow
- GRB 091003: Swift/UVOT Detection of an Optical Afterglow
- GRB 091003: Skynet/DSO Observations
- GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
- GRB 091003: Swift XRT analysis
- GRB 091003A: Fermi LAT detection
- GRB 090926A: Skynet/PROMPT Observations of Day 4 - 6 Fading Rate
- GRB 091003A: Fermi GBM detection
- GRB 090926A: Skynet/PROMPT Observations of Post-Peak Fading
- GRB 090929B, Swift-BAT refined analysis
- Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
- Konus-Wind observation of GRB 090929A
- Konus-Wind observation of GRB 090929B