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"
32183 results found.
- GRB 241128A: Enhanced Swift-XRT position
- GRB 241128A: NOT optical observations
- 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
- GRB 241127A: Swift detection of a burst with an optical counterpart
- LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
- SVOM/GRM observation of GRB 241126B or a short burst from magnetar
- GRB 241126A: SVOM/GRM observation
- IPN triangulation of GRB 241114B
- GRB 241113B: EP-FXT afterglow detection
- 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
- GRB 241113A: Possible ATCA Radio detection
- GRB 241120A: Fermi GBM Observation
- GRB 241114B: Insight-HXMT/HE detection
- 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
- GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
- Fermi GRB 241117A: Global MASTER-Net observations report
- 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
- GRB 241115A: Mephisto upper limits
- GRB 241113B: Mephisto upper limits
- EP241115a/GRB 241115D: Swift/XRT follow-up observation
- GRB 241115D / EP 241115a: SVOM/GRM observation
- GRB 241115A: Fermi GBM Observation
- GRB 241115A: LCOGT Optical Upper Limits
- GRB 241115C: Swift/BAT-GUANO localization skymap of a burst
- Fermi GRB 241115B: Global MASTER-Net observations report
- GRB 241115B: Fermi GBM Final Real-time Localization
- EP241113a: No Detection in Fermi-GBM Observations
- Swift GRB 241115A: Global MASTER-Net observations report
- Fermi GRB 241115A: Global MASTER-Net observations report
- GRB 241115A: Swift detection of a burst
- GRB 241115A: Fermi GBM Final Real-time Localization
- GRB 241113B: KAIT Optical Afterglow Candidate
- LIGO/Virgo/KAGRA S241114bi: Upper limits from Fermi-GBM Observations
- GRB 241113A: Swift-BAT refined analysis
- GRB 241113A: PRIME near-infrared upper limits
- Fermi GRB 241114A: Global MASTER-Net observations report
- GRB 241114A: Fermi GBM Final Real-time Localization
- GRB 241113B: J-band upper limit from WINTER
- GRB 241113A: J-band observations with WINTER
- GRB 241030A: LCO optical observation
- GRB 241113B: Swift-XRT observations
- GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
- GRB 241113A: KAIT optical observations
- EP241113b/GRB 241113B: EP detection of GRB 241113B
- GRB 241113B: SVOM/GRM observation
- GRB 241113A: Swift-XRT refined Analysis
- GRB 241113A: Swift/UVOT Detection
- GRB 241113A: REM detection of the optical/NIR afterglow
- Konus-Wind detection of GRB 241107A (short/hard)
- Fermi Gamma-ray Burst Monitor trigger 753166198/241113201 is not a GRB
- GRB 241113B: Swift ToO observations
- GRB 241113A: LCO optical observations
- GRB 241112B: GMG Optical Upper Limit