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"20386 results found.
- GRB110205A: MITSuME Ishigakijima Optical Observation
- GRB110205A: MITSuME Okayama Optical Observation
- GRB 110205A: Swift/UVOT Continuing Observations
- Observations GRB 110205A
- GRB 110205A: Newcastle Observatory Optical Observations
- GRB 110205A: LOAO B/R Observation
- GRB 110205A: optical flare confirmation
- GRB 110205A: NOT redshift confirmation
- GRB 110205A: Enhanced Swift-XRT position
- GRB 110205A: PAIRITEL NIR Afterglow Detection
- GRB 110205A: Swift/UVOT Confirmation of Flaring Afterglow
- GRB 110205A: TAROT Calern observatory detection of an optical flare
- GRB 110205A: TAROT Calern observatory optical detection
- GRB 110205A: Swift detection of a burst with an optical candidate
- GRB110201A: MITSuME Okayama optical upper limits
- Swift/UVOT observations of GRB110201A
- GRB 110201A: Swift-BAT refined analysis
- GRB 110201A: Swift detection of a burst
- GRB110128A: MITSuME Okayama optical upper limits
- GRB 101112A: Maidanak and CrAO optical observations
- GRB110128A: TNG NIR observations
- GRB 110128A: TAROT-Calern refined analysis
- GRB 110128A: Swift/UVOT observations
- GRB 110128A: WHT redshifts of nearby field galaxies
- GRB 110128A: Enhanced Swift-XRT position
- GRB 110128A: Afterglow detection from NOT
- GRB 110128A: TAROT Calern observatory upper limits
- GRB 110128A: Swift detection of a burst
- GRB 110106B, radio observations
- GRB 110120A: MASTER optical observations
- IPN triangulation of GRB 110120A
- GRB 101225A: CQUEAN optical observation
- GRB 110106A: CrAO optical observations
- GRB 110112A: optical upper limit
- GRB110119: Swift/UVOT Detection
- GRB110119A: MITSuME Okayama optical upper limits
- GRB 110119A: Swift-BAT refined analysis
- GRB 110119A: PAIRITEL NIR Afterglow Detection
- GRB 110119A: Enhanced Swift-XRT position
- GRB 110119A: Swift detection of a burst with an optical detection
- GRB 101219B: tentative redshift and spectroscopic supernova detection
- GRB 101219B: GROND detection of a SN signature
- Swift-BAT trigger 442771 is a noise fluctuation
- GRB 101219B: Likely the GRB host emission dominates now in the uvw2 filter
- New feature in Fermi GBM GRB Ground Position Notices
- Swift-BAT Trigger 442539 is not a GRB
- Swift Trigger 442539 is probably not a GRB
- Short GRB 110112B : early optical limit by "Pi of the Sky"
- GRB 110112B: Swift XRT and UVOT observations of the INTEGRAL burst
- GRB 110112A: MITSuME Akeno and Okayama optical upper limits
- GRB 110107A: Swift-XRT afterglow confirmation
- GRB 110112A: Swift/UVOT upper limits
- GRB 110112A: WHT candidate afterglow/host galaxy
- GRB 110112A: Enhanced Swift-XRT position
- GRB 110112A: Swift detection of a possible short burst
- GRB 110107A: Swift/UVOT upper limits
- GRB 101225a
- GRB 101219b. Possible radio afterglow detection.
- GRB 110107A: Swift-XRT Afterglow Candidate
- Short GRB 110106A: MASTER OT observations
- GRB 110106A: TNG NIR observations
- GRB 110106A: ISAS-Kanazawa optical upper limit
- GRB 110106A: MITSuME Okayama optical upper limits
- GRB 110106B: Enhanced Swift-XRT position
- GRB 110106A: Swift/UVOT Upper Limits
- GRB 110106A: Enhanced Swift-XRT position
- GRB 110106B: Swift detection of a burst
- GRB 110106A: TNG optical observations and candidate counterparts
- GRB 110106A: Swift detection of a burst
- GRB 101225A: Host galaxy
- GRB110102A: Swift/UVOT observations
- GRB110102A: MITSuME Okayama Optical Observation
- GRB 110102A: Enhanced Swift-XRT position
- GRB 110102A: Swift detection of a burst with an optical detection
- GRB 101225A: P60 Observations
- GRB 101225A: MAXI/GSC observations
- GRB 101225A Late-time emission observed by Swift-BAT
- GRB 101225A, Swift-BAT refined analysis
- GRB 101225A: Swift/UVOT Detection
- GRB 101225A: Enhanced Swift-XRT position
- Trigger 441015 / GRB 101225A: Further NOT optical observation
- Trigger 441015 / GRB 101225A: NOT optical afterglow candidate
- GRB 101225A (Swift trigger 441015): optical upper limit
- Trigger 441015: Swift detection of a possible burst or transient
- GRB 101224A: NOT optical observation
- GRB 101224A: Pre-event imaging from DeepSky; Detection of a source in the XRT error circle
- GRB 101224A: Swift/UVOT Upper Limits
- GRB 101224A: Swift-XRT refined Analysis
- GRB101224A: MITSuME Okayama optical upper limits
- GRB 101224A - UVOT-enhanced XRT position
- GRB 101224A: Swift detection of a short burst
- GRB 101219A: Chandra Observations
- GRB 101219B: Swift/UVOT refined analysis
- GRB 101219B: Enhanced Swift-XRT position
- GRB 101219A: MITSuME Ishigakijima Optical upper limits
- GRB 101219B: GROND Detection of the Optical/NIR Afterglow
- GRB 101219A: IAC80 optical observations
- GRB 101219B: Swift detection of a burst with an optical afterglow
- GRB 101219A: Swift/UVOT Upper Limits
- GRB 101219A: GROND Upper limits