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"32494 results found.
- GRB 090123: Swift-BAT refined analysis
- AXP 1E1547.0-5408: long bursts with INTEGRAL SPI-ACS
- GRB 090118: Swift XRT Observations - Confirmation of an Afterglow
- AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
- AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
- AXP 1E1547.0-5408: Fermi GBM observations
- Trigger 340734: Swift detection of a possible short burst
- GRB 090118: Subaru NIR Observation
- GRB 090118: KPNO 4m 2nd Epoch Observations
- GRB 090118 (BATSS): GRT Optical Observation
- GRB 090118: KPNO 4m Detection of Candidate Afterglow
- GRB 090118: Swift-XRT observations
- GRB090118 Swift/UVOT upper limits
- GRB 090118: GROND Upper Limits
- GRB 090117: confirmation of the X-ray afterglow
- GRB 090117 - Fermi GBM Observations
- GRB 090117: GROND Upper Limits
- GRB090117 Swift/UVOT upper limits
- GRB 090112B: Suzaku WAM observation of the prompt emission
- GRB 090113: LOAO Detection Limits in R, I, z, Y-band
- GRB 090113: Swift UVOT upper limits
- GRB 090113: GROND Upper Limits
- GRB 090113: Swift-XRT refined analysis
- GRB 090113: Observations from NOT
- GRB 090113: Swift-BAT refined analysis
- GRB 090113: ROTSE-III Optical Limits
- GRB090113: XRT position
- GRB 090111, Swift-BAT refined analysis
- GRB 090111: Swift UVOT Upper Limits
- GRB 090111: Swift-XRT refined analysis
- GRB 090107B: Suzaku WAM observation of the prompt emission
- GRB090107B: Fermi GBM Detection
- GRB 090102: WSRT Radio Observations
- GRB 090107B: Swift XRT afterglow confirmation
- GRB 090107B: Swift/UVOT Observations
- GRB 090107B: Swift-XRT detection of possible afterglow
- GRB 090107B optical observations
- GRB 090107B: ROTSE-III Optical Limits
- Fermi/GBM detection of GRB 081226A
- GRB 090107: Swift-BAT refined analysis
- GRB 090102: optical decay
- VLA radio upper limit on GRB 090102
- GRB 090102: GRT Optical Observation
- Konus-Wind observation of GRB 090102
- GRB 090102: Hobby-Eberly Telescope Spectroscopy
- GRB 090102: P60 Imaging and P200 Spectroscopy
- GRB 090102 Observations from IAC80
- GRB 090102: GROND observations of the optical afterglow
- Swift UVOT observations of GRB 090102
- GRB 090102: Swift-BAT refined analysis
- GRB 090102: Swift XRT refined analysis
- GRB 090102: NOT redshift
- GRB 090102: TAROT Calern observatory optical light curve
- GRB 090102: REM observations of a bright afterglow
- GRB 081230: GROND confirmation of the afterglow
- GRB 081230, Swift-BAT refined analysis
- GRB081230: Swift-XRT refined analysis
- GRB 081230 Swift/UVOT Observations
- GRB 081230: Swift/UVOT Detection of an Optical Afterglow
- GRB 081230: ROTSE-III Detection of Optical Counterpart
- GRB 081228: GROND confirmation of the optical/NIR afterglow
- GRB 081226B: Fermi GBM observation
- GRB 081228, Swift-BAT refined analysis
- VLA radio detection of GRB 081221
- GRB 081228: Swift/UVOT Upper Limits
- GRB 081228: Swift-XRT Team refined analysis
- GRB 081228: detection by GROND
- VLA radio observation of GRB 081221
- GRB 081226B: Swift XRT and UVOT upper limits
- GRB 081224: Suzaku WAM observation of the prompt emission
- GRB 081226: Swift-XRT refined analysis
- GRB 081226A: Swift UVOT Upper Limits
- GRB 081226: Second epoch of Gemini-South imaging
- GRB 081226A: Swift-BAT refined analysis
- GRB 081226: Gemini-South imaging
- GRB 081226: GROND afterglow candidate
- GRB 081226: ROTSE-III Optical Limits
- GRB 080810: optical observations
- GRB 081211B: optical observations
- GRB081224: LAT retraction
- GRB 081224: Swift-XRT observation
- GRB 081222: MITSuME optical observation
- GRB 080810: optical observations
- Konus-Wind observation of GRB 081222
- GRB 081221: GROND observations
- GRB 081222: Gemini-N confirmation of redshift z=2.77
- GRB 081222:Optical afterglow observation
- VLA radio upper limit on GRB 081222
- GRB 081222: Fermi GBM observation
- GRB 081222: Gemini-South absorption redshift
- GRB081222: Swift/UVOT further observations
- GRB 081221: Probable host galaxy in Keck imaging
- GRB 081222, Swift-BAT refined analysis
- GRB 081221, Swift-BAT refined analysis
- Konus-Wind observation of very bright GRB 081215A
- GRB 081222: Swift XRT refined analysis
- GRB081221: Fermi GBM observation
- Swift/UVOT observations of GRB 081221
- IPN triangulation of bright GRB 081215A
- GRB 081221: Swift-XRT Refined Analysis