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"5386 results found.
- GRB 150817A: Continued RATIR Observations, Revised Candidate
- GRB 150817A: Swift detection of a burst
- GRB 150801A: MAXI/GSC detection
- GRB 150724B: Swift-XRT afterglow detection
- GRB 150727A: Swift detection of a burst with an optical counterpart
- GRB 150724B: Swift-XRT observations
- GRB 150725A: MAXI/GSC detection
- Swift IGR J00291+5934: MASTER Optical flare detection
- GRB 150711A: Swift detection of a burst
- Swift-XRT observations of GRB 150710A
- GRB 150702A: MASTER-SAAO inspection
- GRB 150702A: Swift-XRT observations
- GRB 150608A: Swift-XRT follow-up observations
- GRB 150608A: MITSuME Akeno optical upper limits
- GRB150607A: Discovery Channel Telescope Optical Observations
- GRB 150518A: possible SN observations
- Swift Trigger 642453: a possible GRB
- GRB 150512A: iPTF Optical Observations
- Konus-Wind observation of GRB 150510A
- GRB 150510A: Fermi GBM detection
- GRB 150510A: Fermi-LAT detection
- Confirmation that Swift Trigger 639636 is not astrophysical
- GRB 150430A: MAXI/GSC detection
- GRB 150428B: IRSF NIR upper limits
- GRB 150428B: MASTER-net prompt optical observation
- GRB 150428C/MAXI J0400+678: MAXI/GSC detection
- GRB 150428A: P60 observations
- GRB 150428B: Swift detection of a burst
- GRB 150423A: MITSuME Akeno Optical observation
- GRB 150413A: P60 photometry
- GRB 150403A: MASTER-net optical observation
- GRB 150403A: Fermi GBM Detection
- GRB 150323C: CrAO optical observations
- GRB 150323C: additional optical observations in Mondy
- GRB 150403A: Fermi-LAT detection
- GRB 150323B: Khureltogot optical observations
- GRB 150323C: Nishi-Harima NIR Observations
- GRB 150323A: AAO optical observations
- GRB 150323C: MITSuME Akeno Optical observation
- GRB 150323C; Konkoly optical observations
- GRB 150323B; Konkoly optical observations
- GRB 150323A; Konkoly optical observations
- GRB 150323C: Mondy optical observations
- GRB 150323B : Xinglong TNT upper limit
- GRB 150323C: RATIR Optical Afterglow Observations
- GRB 150323C : Xinglong TNT optical observation
- GRB 150323C: Xingming upper limit
- GRB 150323A: KAIT Optical Observations
- GRB 150323C: Nanshan optical afterglow detection
- GRB 150323C: MASTER-net optical observation
- GRB 150323A: RATIR Optical Afterglow Observations
- GRB 150323A: Swift detection of a burst
- Swift Triggers 635788-635794 are probably not real.
- GRB 150318A: Skynet PROMPT-CTIO Observations
- GRB 150317A: RATIR Optical Afterglow Detection
- GRB 150220A, the review of the sky area in plate archives
- GRB 150314A: NOT further optical observations
- GRB 150314A: P60 observations
- GRB 150314A: NOT optical observations
- GRB 150314A: MITSuME Akeno upper limits
- GRB 150314A: Skynet Yerkes-41 Observations of the Optical Afterglow
- GRB 150313A: MAXI/GSC detection
- GRB 150309A: AAO optic upper limit
- GRB 150311A: MAXI/GSC possible afterglow detection
- GRB 150309A: CrAO optic upper limit
- GRB 150309A: ISON-Kislovodsk optic upper limit
- GRB150309A: Optical observations at Crni Vrh
- GRB 150309A: MASTER prompt optical observation
- GRB 150309A: Swift detection of a burst
- GRB 150305A: Swift XRT confirms weak INTEGRAL event as a new GRB
- Chandra X-ray observations of SWIFT J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka p[PFH2005] 622)
- Swift J0045.2+4151: analysis of XMM-Newton archival data
- BAT trigger 633105 (GRB 150301C): NOT r-band upper limit
- GRB 150302A: Mondy optical upper limit
- GRB 150302A: MITSuME Okayama upper limits
- GRB 150301B: GROND afterglow observations
- GRB 150301B: MASTER early OT detection
- GRB 150301C : (Swift trigger 633105) Swift observations
- GRB 150301A: GROND Observations
- GRB 150301A: Fermi GBM observation
- Swift-BAT refined analysis of magnetar 4U 0142+61 (Trigger 632888)
- Fermi GBM Observations of Magnetar 4U 0142+61
- Trigger 632888: Swift detection of the magnetar 4U 0142+61
- IPN Triangulation of GRB 150220A
- GRB 150222A: GROND optical afterglow candidate
- Trigger 631747: Swift detection of 4U 0614+09
- GRB 150212A: Swift-XRT afterglow detection
- Trigger 630047: Swift detection of 1RXS J180408.9-342058
- GRB 150203A: ISON-NM early optical limit
- GRB 150203A: MITSuME Okayama upper limits
- GRB 150203A: Fermi GBM observation
- GRB 150128A: MASTER OT detction during inspection
- GRB 150123A: MASTER inspection
- GRB 150126A: MAXI/GSC afterglow candidate detection
- GRB 150120B: Swift-BAT refined analysis
- GRB 150120A: P60 optical observations
- Swift detection of 4U 1700+24 (= V* V934 Her)
- GRB 150103A: MASTER optical observations
- Swift J123205.1-105602: XRT and UVOT observations of soft short burst source
- GRB 141230A: Fermi GBM detection