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"19353 results found.
- GRB 070616: Swift XRT refined circular
- GRB 070616: BTA optical observations
- Swift/UVOT observations of GRB070616
- GRB 070616: TLS observation
- Swift XRT observations of the INTEGRAL burst GRB070615: Possible
- GRB 070616, Swift-BAT partial refined analysis
- GRB 070616: Swift detection of a burst
- UVOT Observations of INTEGRAL burst GRB070615
- SWIFT J195509.6+261406 (GRB 070610): further observations
- GRB 070612A: Rapid Decay
- GRB 070612A: Suzaku/WAM observation of the prompt emission
- SWIFT J195509.6+261406 / GRB 070610: OPTIMA-Burst observations
- GRB 070611: Watcher Observations
- Swift Trigger 282176 is Cygnus X-1
- GRB 070612A: MDM Observations
- GRB 070612B, Swift-BAT refined analysis
- GRB 070612A, Swift-BAT refined analysis
- GRB 070612B: Swift-XRT refined analysis
- SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations
- GRB 070612B: Swift/UVOT upper limits
- GRB 070612B: FRAM limit
- GRB 070612B: KAIT limits
- GRB 070612B: Swift XRT position from downlink data
- GRB 070610: TAROT Calern observatory optical observations
- GRB 070612B: Swift detection of a burst
- GRB 070612: Swift detection of a burst
- GRB 070610: Swift-XRT refined analysis
- GRB 070610: TLS RRM sees flaring behaviour - Galactic transient?
- GRB 070611: Swift/UVOT Observations
- GRB 070611: Swift-XRT refined analysis
- GRB 070611, Swift-BAT refined analysis
- GRB 070610: Watcher Observations
- GRB 070611: ROTSE-III Detection of Late Rising Optical Counterpart
- GRB 070611; Swift-XRT position
- GRB 070611: ROTSE-III Optical Limits
- GRB 070611: Swift detection of a burst
- GRB 070610: Swift-UVOT Upper Limits
- GRB 070610: OPTIMA-Burst high-time-resolution optical observations
- GRB 070610, Swift-BAT refined analysis
- GRB 070610; Swift-XRT position
- GRB 070610: Swift detection of a burst
- GRB 070412: TAROT Calern observatory optical observations
- GRB 070411: TAROT Calern observatory optical observations
- Swift/UVOT refined analysis of GRB070531
- GRB 070531: Swift-BAT refined analysis
- GRB 070531: Swift-XRT position
- GRB 070531: Liverpool Telescope Optical Observations
- GRB 070531: Swift detection of a burst
- Swift/UVOT refined analysis of GRB070529
- GRB 070529: MARGE Observations
- GRB 070529: Optical aterglow from MIRO
- GRB 070529: Swift-XRT refined analysis
- GRB 070529, Swift-BAT refined analysis
- GRB 070529: Swift detection of a burst with an optical aterglow
- GRB 070412: Deep Keck imaging
- Swift Triggers 280447, 280450 and 280451 are invalid
- Swift trigger 280447 is probably a Galactic transient
- GRB 070518: MARGE Observations
- GRB 070521: pseudo-z ~ 2.28 from prompt emission spectrum
- Konus-Wind observation of GRB 070521
- GRB 070521: Swift/UVOT Upper Limits
- GRB 070521: Swift-XRT refined analysis
- GROND upper limits of GRB 070521
- GRB 070521 Milagro GeV/TeV Observations
- GRB 070520B: Swift/UVOT Upper Limits
- GRB 070521, Swift-BAT refined analysis
- GRB 070520A: Swift UVOT Upper Limits
- GRB 070520B: Swift-XRT refined analysis
- GRB 070521: TAROT La Silla observatory optical observations
- GRB070521 - SDSS Pre-Burst Observations
- GRB 070521: Swift detection of a burst
- GRB 070520B, Swift-BAT refined analysis
- GRB 070520A, Swift-BAT refined analysis
- GRB 070520A: Swift-XRT refined analysis
- GRB 070520B: Swift detection of a burst
- GRB 070520: Swift detection of a burst
- VLA observation of GRB 070518
- GRB 070518: Swift-XRT refined analysis
- GRB070518: UVOT refined analysis
- GRB 070518, Swift-BAT refined analysis
- GRB 070518: Swift detection of a burst with optical afterglow
- GRB070517: Swift-XRT Refined Analysis
- GRB 070517, Swift-BAT refined analysis
- GRB 070517: Swift detection of a burst
- GRB 070509: objects inside XRT error circle
- GRB 070512: IPN localization and Konus spectrum of a bright burst
- GRB 070508: pseudo-z from 4 different spectral analyses
- GRB 070509: Swift/UVOT Upper Limits
- Konus-Wind and Konus-A observation of GRB 070508
- Swift-BAT trigger 278987 is not a GRB
- GRB 070510: Swift detection of a possible burst
- GRB070509: Swift-XRT Refined Analysis
- GRB 070509, Swift-BAT refined analysis
- GRB 070508: Suzaku/WAM observation of the prompt emission
- GRB 070509: REM observations
- GRB 070509: Swift detection of a burst
- GRB 070509: ROTSE-III Optical Limits
- GRB070508: Swift/UVOT Observations
- GRB 070508, Swift-BAT refined analysis
- GRB 070508: Swift-XRT refined analysis