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.
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subject:"Swift"body:"GRB"submitter:"Judith Racusin"- Konus-Wind observation of GRB 160409A
- GRB 160410A: SMARTS optical/IR observations
- LIGO Virgo G211117: Additional MWA Observations
- GRB 160410A: TLS Tautenburg observations
- GRB 160412A: Swift/UVOT Upper Limits
- Swift Trigger 682614 is not a GRB
- GRB 160410A: JCMT SCUBA-2 sub-mm observation
- GRB 160409A: Swift-XRT observations
- GRB 160409A found in Swift BAT ground analysis
- GRB 160412A: Swift-XRT refined Analysis
- GRB 160411A: Swift-BAT refined analysis of the short burst
- GRB 160412A: Swift-BAT refined analysis
- GRB 160410A: further NOT optical observations
- GRB 160412A: Enhanced Swift-XRT position
- GRB 160412A: Swift detection of a burst
- GRB 160408A: CALET Gamma-Ray Burst Monitor detection
- GRB 160409A: Swift ToO observations
- GRB 160410A: NOT observations of the afterglow
- GRB 160408A: 6.0 GHz VLA upper limit
- GRB 160411A: Gemini-S optical observations
- GRB 160411A: GROND Optical/NIR upper limits
- GRB 160411A: Swift/UVOT Upper Limits
- GRB 160410A: UKIRT near-IR upper limits
- GRB 160411A: Fermi GBM detection
- Konus-Wind observation of GRB 160410A (short/hard)
- GRB 160410A: TAROT La Silla observatory early optical observations
- GRB 160411A: Swift-XRT refined Analysis
- GRB 160410A: MITSuME Akeno optical upper limits
- GRB 160411A: MASTER-NET early optical observations.
- GRB 160411A: Enhanced Swift-XRT position
- GRB 160410A: Swift-XRT refined Analysis
- GRB 160411A: Swift-XRT observations
- GRB 160410A: GMG observation
- GRB 160411A: Swift detection of a short burst
- GRB 160410A: Keck-I/LRIS redshift
- GRB 160410A: Skynet PROMPT-CTIO observations of the optical afterglow
- GRB 160410A: Swift-BAT refined analysis of the short GRB
- GRB 160410A: Swift/UVOT Detection
- GRB 160410A: VLT/X-shooter redshift
- GRB 160410A: Enhanced Swift-XRT position
- GRB 160410A: GROND optical detection
- GRB 160410A: Swift detection of a (possibly-short) burst with an optical counterpart
- GRB 160408A: GMG observation limit
- GRB 160408A: Gemini afterglow confirmation
- GRB 160408A: TLS Tautenburg observations
- GRB 160408A: Swift/UVOT Upper Limits
- GRB 160408A: Swift-XRT refined Analysis
- GRB 160408A: Fermi GBM detection
- GRB 160406A: Fermi GBM observation
- GRB 160408A: Swift-BAT refined analysis
- GRB 160408A: Gemini optical observations
- GRB 160408A: Enhanced Swift-XRT position
- GRB 160408A: Swift detection of a short burst
- IPN Triangulation of GRB 160406A (short/hard)
- LIGO/Virgo G211117: 10.4m GTC follow-up of PS15dpn
- GRB 160401A: Swift-XRT observations
- GRB 160401A: Swift/UVOT Upper Limits
- GRB 160401A: Zadko observatory - Gingin optical observations
- GRB 160401A: LT observations
- GRB 160401A: Swift ToO observations
- GRB 160401A: MASTER-IAC prompt optical observations
- GRB 160401A: a long GRB detected by INTEGRAL
- GRB 160327A: Continued RATIR Optical and NIR Observations
- LIGO/Virgo G211117: LOFAR follow-up
- GRB 160324A: CALET Gamma-Ray Burst Monitor detection
- GRB 160327A: Early RAPTOR Limits
- GRB 160327A: JCMT SCUBA-2 sub-mm observation
- GRB 160327A: Imaging and spectroscopy from GTC
- Konus-Wind observation of GRB 160325A
- GRB 160327A: Continued RATIR Optical and NIR Observations
- GRB 160327A: KAIT optical afterglow confirmation
- GRB 160327A: Mondy optical upper limit
- GRB 160327A: Swift-BAT refined analysis
- GRB 160327A: Swift/UVOT Upper Limits
- GRB 160327A: Swift-XRT refined Analysis
- GRB 160327A: Enhanced Swift-XRT position
- GRB 160327A: RATIR Optical and NIR Afterglow Detection
- GRB 160327A: Swift detection of a burst
- GRB 160325A, Swift-BAT refined analysis
- GRB 160325A: GROND Upper Limits
- GRB 160325A: Swift-XRT refined Analysis
- GRB 160325A: Further Swift/UVOT Observations
- GRB 160325A: afterglow confirmation
- GRB 160325A: Enhanced Swift-XRT position
- GRB160325A Swift/UVOT Detection
- GRB 160325A: Fermi-LAT detection
- Swift Trigger 680457 is not a GRB
- LIGO/Virgo G211117: CALET GBM Observations
- GRB 160325A: Fermi GBM detection
- GRB160325A: REM NIR observations
- GRB 160325A: Swift detection of a burst
- Swift detects GX 301-2 in very high state
- Fermi Gamma-ray Burst Monitor trigger 160323546 is not a GRB
- GRB 160321A: AbAO optical observations
- GRB 160321A: Possible RATIR Optical and NIR Detections
- GRB 160321A: Swift/UVOT Upper Limits
- GRB 160321A: Swift-BAT refined analysis
- GRB 160321A: Swift-XRT refined Analysis
- GRB 160316A: CALET Gamma-Ray Burst Monitor detection
- GRB 160321A: Enhanced Swift-XRT position