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"3051 results found.
- GRB 130427A: Nishi-Harima NIR Observations
- GRB 130427A: T100 observations
- GRB 130427A: Swift-BAT refined analysis
- GRB 130427A: Optical Observations
- GRB 130427A: MAXI/GSC detection
- GRB 130427A: Swift detection of a very bright burst with a likely bright optical counterpart
- GRB 130420A: Redshift from 10.4m GTC
- GRB 130327A: Gemini Observations
- GRB 130327A: ISON-NM optical upper limit
- GRB 130327A: Enhanced Swift-XRT position
- GRB 130327A: Swift detection of a burst
- GRB 130325A: Fermi GBM detection
- GRB 130315A, Swift-BAT refined analysis
- GRB 130305A: Gemini-North upper limit
- GRB 121128A: optical observations in Mondy observatory
- GRB 130211A: Swift-XRT refined Analysis
- GRB 130211A: GROND detection of the afterglow
- GRB 130206A: GROND Observations
- GRB 130102B: MAXI/GSC detection
- GRB 121201A: Swift/UVOT Detection
- GRB 121201A: a GRB with an optical counterpart
- GRB 121108A: MITSuME Ishigakijima upper limits
- GRB 121027A - Gemini South spectroscopy
- GRB 121011A: MASTER-Net bell light curve
- Trigger 535733: Swift possible detection of SAX J1828.5-1037
- IPN Triangulation of long GRB 120919B
- IPN Triangulation of long GRB 120919A
- Swift Trigger 534017 is probably not real.
- IPN Triangulation of long GRB 120916A
- GRB 120913A: Swift-BAT refined analysis
- GRB 120911A: optical upper limit ISON-NM
- IPN Triangulation of GRB 120911B (long/bright)
- GRB 120908A: MAXI/GSC detection
- GRB 120909A: Swift detection of a burst
- GRB 120830A: Swift-XRT and UVOT observations
- GRB 120817A: FTN and FTS observations
- GRB 120817A: Swift detection of a burst
- GRB 120811A: Swift/XRT-UVOT Obseravations
- Improved IPN error box for short hard GRB 120811B
- GRB 120803A: Swift detection of a possible burst
- GRB 120802A: MASTER optical observations
- Trigger 529076: Swift possible detection of SwJ1910.2-0546
- GRB 120724A: FTN optical afterglow candidate
- GRB 120712A: Fermi GBM observation
- GRB 120712A: Swift detection of a burst with optical afterglow
- GRB 120709A: optical afterglow limits
- GRB 120703A: NOT optical observation
- GRB 120630A: Swift-BAT/-XRT/-UVOT refined analysis
- Watcher follow-up observations of IGR J17062-6143 (Swift trigger 525148)
- Skynet/PROMPT observations of IGR J17062-6143 (Swift trigger 525148)
- Swift detection of IGR J17062-6143
- GRB 120622A: MAXI/GSC detection
- GRB 120528B: MAXI/GSC detection
- GRB 120521C: EVLA Localization of Afterglow
- GRB 120521C: Early Tautenburg limits
- GRB 120521A: Swift detection of a short burst
- GRB 120510A: MAXI/GSC detection of a burst
- GRB 120422A: Additional Gemini observations and Keck/LRIS spectroscopy
- GRB 120404A: optical observations in Mondy observatory
- GRB 120404A: MITSuME Okayama Optical Observation
- Konus-Wind observation of GRB 120323A
- GRB 120324A: Liverpool Telescope optical candidate
- GRB 120320A , optical observations
- IPN Triangulation of GRB 120316A
- GRB 120308A: Swift detection of a burst
- Konus-Wind observation of GRB 120226A
- GRB 120215A: MITSuME Okayama Optical upper limits
- Skynet/PROMPT observations of GRB120215A
- GRB 120212A: MITSuME Ishigakijima Optical Observation
- GRB 120211A: Swift-BAT refined analysis
- GRB 120119A: GRT detection of early afterglow
- GRB 120121A: Swift detection of a burst
- GRB 120102A, the review of the sky area in plate archive
- AXP 4U 1042+61: Mondy optical observations
- INTEGRAL Weak trigger #6433: GRT Optical Observation
- GRB 120106A: Swift detection of a burst
- GRB 120102A: Swift-BAT refined analysis
- GRB 120102A: Swift/UVOT Detection
- GRB 120102A: Enhanced Swift-XRT position
- GRB 120102A: Swift detection of a burst with an optical counterpart
- GRB 111229A: Swift/UVOT Detection
- GRB 111229A: Enhanced Swift-XRT position
- GRB 111229A: GROND afterglow candidate
- GRB 111229A: Swift detection of a burst
- GRB 111228A, Swift-BAT refined analysis
- GRB 111103B: optical upper limit
- GRB 111209A: IRTF NIR Imaging/Spectroscopy
- GRB 111129A: Swift/UVOT Detection
- GRB 111129A: Enhanced Swift-XRT position
- GRB 111129A: Swift detection of a burst with an optical counterpart
- GRB 111126A found in ground analysis of BAT data
- GRB 111107A: Swift-XRT refined Analysis
- GRB 111103B: optical observations
- GRB 111024A: MAXI/GSC detection of a burst
- EVLA 22 GHz Detection of GRB 111008A
- GRB 111008A: Gemini spectroscopic redshift
- GRB 111008A, GROND observations
- GRB 111008A: Gemini optical counterpart
- GRB 111008A: Enhanced Swift-XRT position
- GRB 111008A, Swift-BAT refined analysis,