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"38929 results found.
- LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
- EP241201a: Global MASTER-Net observations report
- GRB 241127B: detection of a long GRB by SVOM/ECLAIRs
- GRB241201B: Fermi GBM Final Localization
- GRB241201B: Fermi GBM Final Localization
- Fermi GRB 241201A: Global MASTER-Net observations report
- GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
- GRB 241130A: Fermi GBM Final Real-time Localization
- GRB 241130A: Fermi GBM Final Real-time Localization
- EP241126a: 1.6m Mephisto Optical Upper Limits
- GRB 241201A: Fermi GBM Final Real-time Localization
- Fermi trigger No 754701230: Global MASTER-Net observations report
- IPN triangulation of GRB 241128B
- Konus-Wind detection of GRB 241114B
- GRB 241128A: AbAO optical upper limit
- GRB 241128C: SVOM/GRM observation
- GRB 241128B: SVOM/GRM observation
- GRB 241128A: Swift-BAT refined analysis
- GRB 241127A: Swift-BAT refined analysis
- GRB 241127A: PRIME near-infrared detection
- GRB 241128A: Mondy optical observations
- GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
- 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: NOT optical observations
- GRB 241128A: LCO optical detection
- GRB 241128A: 1.5m OSN optical afterglow detection
- LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
- Fermi trigger No 754492985: Global MASTER-Net observations report
- 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
- IceCube Alert 241127.59: Global MASTER-Net observations report
- 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
- SVOM/GRM observation of GRB 241126B or a short burst from magnetar
- GRB 241126A: SVOM/GRM observation
- IPN triangulation of GRB 241114B
- EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
- EP241126a: GSP detects optical counterpart
- EP241126a: TRT optical counterpart detection
- GRB 241113B: EP-FXT afterglow detection
- LIGO/Virgo/KAGRA S241125n: Gaoyazi/GOT optical observations
- SVOM/GRM detection of a short burst from SGR 1830
- LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
- Konus-Wind detection of GRB 241115D / EP 241115a
- LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
- GRB 241026A: radio detection with the VLA
- LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
- 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
- GRB 241113B: SVOM/VT optical afterglow observations
- 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
- GRB 241120A: CALET Gamma-Ray Burst Monitor detection
- EP241021a and EP241026b: Keck/LRIS spectroscopic observations
- EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
- EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
- GRB 241120A: Mondy and AbAO optical observations
- EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event
- EP241119a: GIT optical upper limits
- GRB 241113A: Possible ATCA Radio detection
- GRB 241120A: Fermi GBM Observation
- GRB 241114B: Insight-HXMT/HE detection
- Integral GRB241120.25: Global MASTER-Net observations report
- EP241119a: Global MASTER-Net observations report
- GRB241120A: a long GRB detected by INTEGRAL
- GRB 241120A: Fermi GBM Final Real-time Localization
- GRB 241115A: CALET Gamma-Ray Burst Monitor detection
- GRB 241112B: Mephisto further optical observations
- GRB 241119A: Fermi GBM Final Real-time Localization
- GRB 241030A: J-band observations
- 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
- Fermi GRB 241118A: Global MASTER-Net observations report
- GRB 241118A: Fermi GBM Final Real-time Localization
- GRB 241117A: SVOM/GRM observation of a short burst with extended emission
- GRB 241117A: Fermi GBM Detection
- Fermi GRB 241117B: Global MASTER-Net observations report
- GRB 241117B: Fermi GBM Final Real-time Localization