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.
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"27774 results found.
- GRB241201B: Fermi GBM Final Localization
- GRB241201B: Fermi GBM Final Localization
- GRB 241130A: Fermi GBM Final Real-time Localization
- GRB 241130A: Fermi GBM Final Real-time Localization
- GRB 241201A: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 241128B
- Konus-Wind detection of GRB 241114B
- LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
- SVOM/GRM observation of a short burst from soft gamma repeater Kes 73
- GRB 241128A: Swift-BAT refined analysis
- GRB 241127A: Swift-BAT refined analysis
- GRB 241127A: PRIME near-infrared detection
- GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
- Swift-XRT observations of IceCube -241127A
- Swift GRB 241128A: Global MASTER-Net observations report
- GRB 241128A: Swift-XRT refined Analysis
- GRB 241129A: Fermi GBM Final Real-time Localization
- GRB 241128A: Enhanced Swift-XRT position
- GRB 241128A: LCO optical detection
- GRB 241128A: 1.5m OSN optical afterglow detection
- GRB 241128A: Swift-XRT afterglow detection
- GRB 241128A: Swift detection of a burst
- GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
- GRB 241127A: Swift/UVOT Detection
- GRB 241127A: Swift-XRT refined Analysis
- GRB 241127A: SVOM/GRM observation
- GRB 241127A: Enhanced Swift-XRT position
- GRB 241127A: LCOGT (40-cm) optical counterpart detection
- Swift GRB241127.91: Global MASTER-Net OT detection
- EP241126a: WFST Observations
- LIGO/Virgo/KAGRA S241125n: Update on Coincidence False Alarm Method
- GRB 241127A: Swift detection of a burst with an optical counterpart
- Swift GRB241127.91: Global MASTER-Net observations report
- Swift GRB241127.91: Global MASTER-Net OT detection
- LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
- LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
- IceCube-241127A: IceCube observation of a high-energy neutrino candidate track-like event
- LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
- EP241126a: Optical Upper limits with Kinder observations
- IPN triangulation of GRB 241114B
- EP241126a: EP-FXT follow-up observation update
- EP241126a: GSP detects optical counterpart
- EP241126a: TRT optical counterpart detection
- EP241126a: EP detection of a fast X-ray transient
- LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
- LIGO/Virgo/KAGRA S241125n: SAGUARO follow-up observations with the MMT
- Trigger_18947: Swift ToO observations (retracted)
- GRB 241113B: EP-FXT afterglow detection
- LIGO/Virgo/KAGRA S241125n: DDOTI Optical Upper Limits
- LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
- SVOM/GRM detection of a short burst from SGR 1830
- GECAM detection of a short burst from SGR 1830
- LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
- LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
- Konus-Wind detection of GRB 241115D / EP 241115a
- GRB 241026A: radio detection with the VLA
- EP241125a: EP detection of an X-ray transient
- LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
- LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
- LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
- LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
- LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
- LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
- LIGO/Virgo/KAGRA S241125n: Updated Sky localization and Coincidence with External Event
- LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
- GRB 241120A: GRBAlpha detection
- Konus-Wind detection of GRB 241117A
- GRB 241105A: ATCA radio detection
- IPN triangulation of GRB 241117A
- GRB 241026A: VIRT Optical Upper Limit
- GRB 241025A: VIRT Optical Upper Limit
- Konus-Wind detection of GRB 241120A
- GRB241120A: OHP/T193 optical observations
- GRB 241120A: CALET Gamma-Ray Burst Monitor detection
- EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event
- GRB 241113A: Possible ATCA Radio detection
- GRB 241114B: Insight-HXMT/HE detection
- EP241119a: EP detection of a fast X-ray transient
- GRB 241120A: Fermi GBM Final Real-time Localization
- GRB 241115A: CALET Gamma-Ray Burst Monitor detection
- GRB 241119A: Fermi GBM Final Real-time Localization
- GRB 241115a: PRIME near-infrared upper limits
- GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
- LIGO/Virgo/KAGRA S241116cq: Upper limits from Swift/BAT-GUANO
- GRB 241115B: Fermi GBM Observation
- GRB 241118A: Fermi GBM Final Real-time Localization
- GRB 241117A: Fermi GBM Detection
- GRB 241117B: Fermi GBM Final Real-time Localization
- GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
- GRB 241117A: Fermi GBM Final Real-time Localization
- GRB 241115C: Fermi GBM Observation
- GRB 241115A: Swift-XRT afterglow detection
- EP241115a/GRB 241115D: Optical upper limits with Kinder observations
- EP241115a/GRB 241115D: Swift/XRT follow-up observation
- EP241113a: Swift XRT weak detection
- GRB 241115A: Fermi GBM Observation
- GRB 241115A: LCOGT Optical Upper Limits
- GRB 241115C: Swift/BAT-GUANO localization skymap of a burst
- GRB 241115B: Fermi GBM Final Real-time Localization
- EP241115a: EP detection of a fast X-ray transient