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"35354 results found.
- GRB 060218: rebrightening
- GRB 060218: emergence of the underlying SN spectrum
- GRB 060218: Decline in r-band flux
- GRB 060218: spectroscopic observations
- GRB 060218: Further refined analysis of the Swift-BAT burst
- GRB 060218: Likely an underluminous GRB
- GRB060218: Optical Spectroscopy of GRB-SN
- GRB060218: VLT spectroscopy
- GRB 060218: Optical Observations at Xinglong Obs.
- GRB 060219: SDSS galaxy inside XRT error circle
- GRB060218: UV Detection and Light Curves
- GRB060219: SARA Observations
- GRB 060219: Swift/UVOT Upper Limits
- GRB 060219: Swift-XRT Team refined analysis
- GRB 051221B: Swift-XRT Team Refined Analysis
- GRB 060219: Partial refined analysis of the Swift-BAT burst
- GRB060218: Radio Afterglow Discovery
- GRB 060219: Swift-XRT position typo correction
- GRB 060218: MDM Redshift
- GRB 060219: Swift-XRT position
- GRB 060218: optical/nIR observations at La Palma
- GRB060219: SDSS pre-burst observations
- GRB 060219: Swift-BAT detection of a weak burst
- Oddball GRB 060218, transient or GRB?
- GRB060218: Swift/XRT Team preliminary analysis of the possible burst
- Brightening of the Optical Counterpart of the Possible GRB 060218
- GRB 060218: MDM Observations
- GRB 060218: Pre-burst detection of a possible host galaxy
- GRB 060218A: ROTSE-III Possible Optical Flare
- Preliminary refined analysis of the Swift-BAT trigger 191157
- Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
- GRB 060211B: Swift/UVOT Upper Limits
- GRB060218 : SDSS pre-burst observations
- GRB 060218: Swift XRT Position
- GRB 060218: Swift-BAT detection of a possible burst
- GRB 060213: optical afterglow not confirmed
- Swift UVOT observations of GRB060213
- GRB 060211B: Skynet Observations
- GRB 060213: optical afterglow candidate
- GRB060213: Swift XRT observations and possible afterglow candidate
- GRB 060213: pseudo-z = 3.5 +/- 0.35 from spectral parameters
- GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths
- GRB060213: MASTER final result
- GRB 060211b: WIRO NIR Observations
- GRB060213:_MASTER_optical_observation
- Konus-Wind observation of bright hard GRB 060213
- GRB 060213: IPN localization
- GRB 060210: Radio Observations
- GRB 060211a: WIRO NIR Observations
- GRB060211B: REM optical and NIR observations
- GRB 060211B: BAT detects no additional burst emission beyond T + 122 sec
- GRB 060211A: Further refined analysis of the Swift burst
- GRB060121: optical observations
- GRB060110: optical observations
- GRB060105: optical observations
- GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
- GRB 060211b: P60 Observations
- GRB 060211A: Partial refined analysis on the Swift-BAT burst
- GRB 060206: SOAR Detections
- GRB 050826: Optical Afterglow and Host Galaxy
- GRB 060210: Further refined analysis of the Swift-BAT burst
- GRB 060211B: Swift/BAT refined analysis
- GRB060210: Swift/UVOT Upper Limits
- GRB 060211B: Swift-XRT Team refined analysis
- GRB060211b: optical observation
- GRB 060210: Optical Observations
- GRB060211.7: MASTER_optical_observation under the snow
- GRB 060211A: Swift XRT Team Refined Analysis
- GRB 060211B: Swift-BAT detection of a burst
- GRB060211: Faulkes North observation
- GRB 060211: ROTSE-III Optical Limits
- GRB 060211: Swift detection of a long burst
- GRB 060210: Refined analysis of the Swift-BAT burst
- GRB060210: Swift XRT Refined Analysis
- GRB060206, optical observations
- GRB 060210 : Xinglong and Lulin optical limit
- GRB060210: Gemini absorption spectroscopy
- GRB 060210: optical evolution
- GRB060210:Faulkes Telescope North Afterglow Confirmation
- GRB 060210: candidate afterglow
- GRB 060210: Swift detection of a burst
- GRB 060206: Swift/UVOT Observations
- Swift-BAT trigger 180931 is not a GRB
- GRB060209: RTT150 optical observations
- GRB 060209 : TAROT optical observation
- GRB060209A: MASTER optical observation
- GRB 060209(?): Swift-BAT detection of a possible burst
- GRB 060206: near-infrared observations (JK' imaging)
- GRB 060206: WSRT Radio Observations
- GRB 060203: Swift/UVOT upper limits
- GRB 060206: TTT Observations
- GRB 060206: More PROMPT Detections
- GRB 060121 : WIDGET Pre-trigger limit
- GRB 060206: Tenagra II Observations
- GRB 060206: PROMPT Detections
- Retraction of orphan GRB afterglow candidate
- GRB060204a: Swift XRT Source is not GRB Afterglow
- GRB 060206: optical observations at Asiago
- Orphan GRB Afterglow candidate
- GRB 060204b: pseudo-z from spectral parameters of the prompt emission