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"114 results found.
- The EP-WXT trigger 01709306297 is likely the known LMXB 4U 1745-203
- The EP-WXT trigger 01709291839 is likely the known LMXB 4U 1745-203
- Fermi GRB 250916A: Global MASTER-Net observations report
- GRB 240315B: AstroSat CZTI detection
- GRB 231129C: AGILE detection
- LIGO/Virgo S230525a: Global MASTER-Net observations report
- GRB230414B: VIRT Optical Upper Limit
- Fermi GRB 210615A: Global MASTER-Net observations report
- Fermi GBM observation of a bright burst from magneta
- LIGO/Virgo S200208q: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S200208q: Identification of a GW compact binary merger candidate
- Fermi trigger No 588838851 Global MASTER-Net observations report
- GRB180523B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 548793993)
- Swift triggered on SAX J1806.5-221
- GRB 161214B: Swift detection of a burst
- GRB 160409A found in Swift BAT ground analysis
- Trigger 659734: Swift detection of SAX J1750.8-2900 or other source near Galactic center
- Konus-Wind observation of GRB 151006A
- Swift detection of SAX J1808.4-3658
- Swift detection of SAX J1712.6-3739
- Swift-BAT trigger 536502 is not astrophysical
- Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
- Swift-BAT trigger 535733 is not astrophysical
- Trigger 535733: Swift possible detection of SAX J1828.5-1037
- SAX J1818.6-1703: Swift detection (trigger 306379)
- UVOT observations of SAXJ1810.8-2609
- Swift detection of a outburst from SAX J1810.8-2609
- GRB060604: Swift/UVOT detections
- GRB 060206: RAPTOR observations of afterglow candidate variability.
- H11603: An X-ray flare from V4641 Sgr, or a possible XRF
- IPN triangulation of GRB030717 (annulus)
- BeppoSAX GRB : GRB020409
- GRB020322: Candidate Optical Afterglow
- Bepposax GRB020322 The second springtime BSAX GRB
- GRB 011211 Optical Observations: Likely Afterglow
- Detection of the X-ray afterglow of GRB011121 by BeppoSAX
- GRB011121: BeppoSAX-WFC refined positions
- BEPPOSAX GRB011121
- The X-ray Flash 011030 ('GRB 011030')
- IPN triangulation of GRB010629
- Support extension to the BeppoSAX mission
- GRB010222: possible optical counterpart
- GRB010222
- GRB 010214, Optical Observations
- GRB000528, Radio Observations
- IPN triangulation of GRB000516
- BeppoSAX GRB000424
- GRB000419 [IPN Position]
- 1SAXJ1715.0-7134 refined position
- RE: Budget cuts in BeppoSAX operations: impact on GRB observation
- X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
- Budget cuts in BeppoSAX operations: impact on GRB observations
- GRB000226 [IPN Position]
- GRB 000210: BATSE Observations
- GRB000210, Radio Observations
- SAX_WFC_GRB_NOTICE
- SAX_WFC_GRB_NOTICE
- GCN resumes full operations
- IPN error box for GRB991216
- GRB 991217 (SAX J2303.2+0015) Optical observations
- GRB991217/SAX J2303.2+0015, optical observations
- SAX J2303.2+0015 Optical observations
- GRB 991217 (SAX J2303.2+0015) Optical observations
- GRB 991217
- SAX J2303.2+0015: an x-ray/GRB?
- BeppoSAX NFI Observation of GRB991106
- GRB 991105: BATSE Observations
- BeppoSAX refined position for GRB991106
- GRB991105: SAX-GRBM/-WFC detection
- BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
- GRB ALERT: GRB991105
- GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
- GRB990908, another BeppoSAX-GRBM/WFC burst detection
- GRB990806 BeppoSAX follow up
- GRB 990712
- Infrared and Optical Observations of GRB990705
- GRB990704: SAX-NFI results summary
- GRB 990704 X-ray Observations
- GRB990705: Intriguing Positional Coincidences
- X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
- optical observation of the X-ray/GRB transient SAX J0835.9+5118
- Optical report on X-ray/GRB transient
- BeppoSAX: A new fast X-ray transient
- GRB990123, Probability of gravitational lensing
- GRB990123 IPN annulus
- GRB990123, refined SAX-WFC position
- GRB 981226 Optical Observations
- GRB981226 BeppoSAX follow up
- GRB980425: X-ray revised positions
- GRB980519, Optical Observations
- GRB980703, Host galaxy multicolor photometry
- GRB 980703 (NFI observations)
- BeppoSAX NFI observations of GRB 980703
- GRB980703
- GRB980613, optical observations
- GRB 980613 Optical Observations
- GRB980613 BeppoSAX-NFI follow up
- GRB980613, BeppoSAX WFC positions
- GRB980519 IPN POSITION
- GRB980515: SAX-WFC updated position