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"19042 results found.
- GRB 160121A: RATIR Optical Observations
- GRB 160121A: Swift/UVOT Upper Limits
- GRB 160121A: GROND Afterglow observations
- GRB 160121A: TSHAO optical afterglow confirmation
- GRB 160121A: Enhanced Swift-XRT position
- GRB 160121A: 1.8m MOA optical afterglow detection
- GRB 160117B: RATIR continued observations
- GRB 160121A: Swift detection of a burst
- GRB 160117A: Swift-XRT afterglow detection
- GRB 160117B: further RATIR observations
- GRB 160119A: afterglow confirmation from the NOT
- GRB160119A: BOOTES-2/TELMA Early Upper Limits
- GRB 160119A: Swift/UVOT Upper Limits
- LIGO/Virgo G184098: MASTER final result
- GRB 160119A: GROND optical/NIR afterglow observations
- GRB 160119A: RATIR Optical and NIR Observations
- GRB 160117B: RATIR Optical and NIR Observations
- GRB 160119A: Enhanced Swift-XRT position
- GRB 160119A: NOT and GTC afterglow candidate
- GRB 160117B: Early iTelescope observation
- GRB 160119A: Swift detection of a burst
- GRB 160117A: Swift/UVOT Upper Limits
- GRB 151228B: AbAO optical upper limit
- GRB 160104A: ISON-Ussuriysk optical observations
- GRB 160117B: GROND optical/NIR afterglow observations
- GRB 160117B: Swift/UVOT Detection
- GRB 160117B: Enhanced Swift-XRT position
- GRB 160117B: LCOGT-SSO optical observations
- Konus-Wind observation of GRB 160113A
- GRB 160117B: Swift detection of a burst with optical counterpart
- GRB 160106A: CALET Gamma-Ray Burst Monitor detection
- IPN Triangulation of GRB 160113A
- LIGO/Virgo G211117: Further Swift-XRT sources
- IPN Triangulation of GRB 160111A (short/hard)
- GRB 160113A: Swift ToO observations
- GRB 160104A: Swift/UVOT Detection
- IPN Triangulation of GRB 151231A
- IPN Triangulation of GRB 151229B (extremely intense/long)
- LIGO/Virgo G211117: iPTF Observations of PS15dpn
- LIGO/Virgo G211117: Pi of the Sky observations
- LIGO/Virgo G211117: VISTA imaging
- LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
- IPN Triangulation of GRB 151225A (short/hard)
- GRB 160104A: Nishi-Harima MINT Observations
- GRB 160104A: Mini-GWAC upper limit during prompt emission phase
- GRB 160104A: GWAC upper limit during prompt emission phase
- GRB 160104A: MITSuME Okayama upper limits
- LIGO/Virgo G211117: INAF TNG follow-up of Kanata telescope candidate
- GRB 160104A: Enhanced Swift-XRT position
- GRB 160104A: MITSuME Okayama Ks-band upper-limit
- GRB 160104A: Swift detection of a burst
- GRB 160101A: CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo G211117: Gemini classification of 7 Pan-STARRS transients
- LIGO/Virgo G211117: LOFAR follow-up
- GRB 160102A: Swift-XRT observations
- GRB 160101A: MITSuME Akeno optical upper limits
- LIGO/Virgo G211117: CSS/CRTS observations on 29/30 Dec 2015 UT
- GRB 160102A: Tiled Swift observations
- GRB 160101B: Fermi-LAT detection
- GRB 160101A: Swift/UVOT Detection
- GRB 160101A: Tiled Swift observations
- LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
- Trigger 668879: Swift detection of V 404 Cyg again
- Trigger 668877: Swift detection of V 404 Cyg
- LIGO/Virgo G211117: MAGIC very-high energy gamma-ray observations
- LIGO/Virgo G211117: INAF TNG follow-up of MASTER OT J020906.21+013800.1
- LIGO/Virgo G211117: OAO-WFC NIR follow-up observations
- IPN Triangulation of GRB 151227B
- GRB 151228B: Swift/UVOT Detection
- LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
- LIGO/Virgo G211117: List of near-term future observation regions by Project Mini-GWAC of SVOM
- LIGO/Virgo G211117: iPTF Optical Transient Candidates
- GRB 151229A: MITSuME Okayama upper limits
- GRB 151229A Swift-BAT Spectral lag analysis
- GRB 151229A: Swift-XRT refined Analysis
- GRB 151228A: Swift-BAT refined analysis
- GRB 151229A: Swift/UVOT observations
- GRB 151229A: Enhanced Swift-XRT position
- GRB 151228B: Swift-XRT refined Analysis
- GRB 151228A: T60 observations
- GRB 151229A: Swift detection of a short burst
- LIGO/Virgo G211117: DESGW program observations with DECam
- GRB 151228B: Enhanced Swift-XRT position
- LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
- LIGO/Virgo G211117: Fermi GBM Observations
- GRB 151228B: Swift detection of a burst with an optical detection
- LIGO/Virgo G211117: MASTER Observations and Inspection + OT
- LIGO/Virgo G211117: INTEGRAL was inactive at the time of the event
- LIGO/Virgo G211117: INAF VST-ESO PARANAL observations
- GRB 151227B: Fermi GBM detection
- GRB 151212A iTelescope observation
- GRB 151221A: INTEGRAL detection of a short burst or possible SGR
- LIGO/Virgo G184098: Fermi-LAT search for high-energy gamma-ray counterpart
- GRB 151215A: TSHAO optical observations
- GRB151215A: Continued P60 Observations
- GRB151215A: Early optical light curve from pt5m, La Palma
- GRB151215A: Swift/UVOT detection
- GRB 151215A: Enhanced Swift-XRT position
- GRB 151215A: GROND Detection of the Optical/NIR Afterglow
- GRB 151215A: Swift detection of a burst