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"11841 results found.
- SGR 1833-0832 is pulsed at 7.56 seconds
- SGR 1833-0832 is pulsed at 7.56 seconds
- Possible pulsation period in SGR 1833-0832
- Discovery of the Spin Period of SGR 1833-0832
- GRB 100319A: correction to GCN 10527
- Probable SGR 1833-0832: Swift-XRT refined analysis
- Probable SGR 1833-0832: Enhanced Swift-XRT position
- Swift-XRT refined position of the probable new SGR 1833-0832
- Swift-BAT refined analysis of the probable new SGR 1833-0832
- GRB 100219A: MASTER-Net optical alert observations
- GRB 100319A: Swift detection of a burst; possible SGR
- GRB 100316D: Further Gemini observations
- GRB 100316B: Swift-XRT refined analysis
- Tentative redshift of GRB100316D from X-ray data
- GRB 100316C: Swift-XRT team refined analysis
- GRB 100316D: Swift XRT refined analysis
- GRB 100316A: Swift-XRT refined analysis
- GRB 100316A: Swift-BAT refined analysis
- GRB 100316B: Swift-BAT refined analysis
- GRB 100316C: BOOTES-3 observations
- XRF 100315A: MAXI/GSC detection of a short X-ray transient
- GRB 100316C: Swift detection of a burst
- GRB 100316B: Swift detection of a burst with optical counterpart
- GRB 100305A: Super-LOTIS early observations
- GRB 100305A: Swift-XRT refined analysis
- GRB 100305A Optical Observations
- GRB 100305A: Swift detection of a burst
- GRB 100302A: Swift-XRT refined analysis
- GRB 100302A: Optical observations at Crni Vrh
- GRB 100302A: Swift detection of a burst
- GRB 100224A SHB found in ground analysis of BAT data
- GRB 100225A: Fermi LAT detection
- GRB 100225A: Fermi GBM detection
- GRB
- GRB 100219A: XRT refined analysis
- GRB 100219A - Gemini South Spectroscopy
- GRB100219A Akeno and Okayama MITSuME Optical Observation
- GRB 100219A: GROND observations
- GRB 100219A: Swift detection of a burst
- GRB 100213B: Swift XRT refined analysis
- GRB 100213A: SARA observations
- GRB 100205A: Keck limits on an underlying host galaxy
- GRB 100206A: YNAO-GMG observations
- GRB 100206A: WHT candidate afterglow
- GRB 100205A: Swift XRT refined analysis
- GRB 100205A: Swift detection of a burst
- Short X-ray Transient detected by MAXI/GSC
- Konus-Wind observation of GRB 100119A
- GRB 100115A: Swift-XRT refined analysis
- Konus-Wind observation of GRB 100116A
- GRB 100117A: Swift-XRT refined analysis
- GRB 100117A: Swift detection of a short hard burst
- GRB 100116A: Fermi LAT detection
- GRB 100115A: SARA Afterglow Candidate
- GRB 100115A: Swift-XRT candidate afterglow
- GRB 100111A: PAIRITEL NIR Upper Limits
- GRB100111A: Swift-XRT refined analysis
- GRB 100111A: Swift detection of a burst with an optical afterglow
- Swift Trigger #382159 is due to XTE J1752-223
- GRB 100103A: GROND Upper Limits
- Konus-Wind observation of GRB 100103A
- GRB 100103A: a long GRB detected with INTEGRAL
- Swift Trigger 381591 is probably not a burst
- GRB 091221: Fermi GBM Observation
- GRB 091221 Swift-BAT refined analysis
- GRB 091221: ROTSE-III Detection of Optical Counterpart
- GRB 091221: Swift detection of a burst
- Konus-Wind observation of GRB 091208A
- GRB 091208B: GAO 150cm telescope Optical Observation
- GRB 091208B: optical observations
- GRB091208B: NOT optical observations
- GRB 091208B: Swift-XRT refined analysis
- GRB 091208B: Swift detection of a burst with an optical afterglow
- GRB 091208: ROTSE-III Optical Limits
- Short X-ray Transient, RIMOTS optical upper limits
- GRB 091109A: GROND confirmation of redshift z = 3.5
- GRB091202: Swift-XRT refined analysis
- GRB 091126A: Suzaku WAM observation of the prompt emission
- Short X-ray Transient Detection by MAXI/GSC
- Konus-Wind observation of very long GRB 091123
- Konus-Wind observation of GRB 091127
- GRB 091127: MASTER early optical transient polarimetry
- GRB 091127: Swift-XRT afterglow detection and analysis
- GRB 091127: TAROT La Silla observatory optical decay
- Konus-Wind observation of GRB 091120
- GRB 091120: MAXI GSC detection
- GRB 091120: Fermi GBM observation
- Konus-Wind observations of GRB 091117A
- Konus-Wind and Konus-RF observations of GRB 091031
- GRB 091031: Fermi LAT detection of a faint burst
- GRB 091112: Swift detection of a possible burst
- GRB 091109B: Swift-XRT Team refined analysis
- GRB 091109B: ROTSE-III Optical Limits
- GRB 091109B: Swift detection of a short burst
- GRB091109: Correction to GCN 10139
- GRB 091109: Swift-XRT refined analysis
- GRB 091109: Swift/UVOT observations
- GRB 091109: Faulkes Telescope South observations
- GRB091109: REM detection of the NIR afterglow
- GRB 091109: Swift detection of a burst with optical afterglow