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"16159 results found.
- GRB 241209A: GRANDMA/TAROT upper limit
- GRB 241209B: BOOTES-5 optical upper limit
- LIGO/Virgo/KAGRA S241102br: continued GRAWITA observations and detection of an optical transient (AT2024adip)
- GRB 241209A: REM optical/NIR observations
- GRB 241209D: Swift detection of a burst
- GRB 241209A: VLT optical observations
- GRB 241209A: GOTO optical upper limits
- EP241206a: 1.5m OSN optical limit
- AT2024adec: X-ray Upper Limits from EP-FXT Observation
- EP241206a: BOOTES Global Network optical limits
- GRB 241207C: MASTER optical observations
- GRB 241206B: GWAC-F50A optical upper limit
- EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
- EP241201a: 1.6m Mephisto Optical Upper Limits
- GRB 241204A: COLIBRÍ Optical Upper Limit
- EP241202b: KAIT optical upper limit
- EP241202b: Kinder optical counterpart candidate
- EP241201a: BOOTES-5 optical upper limit
- EP241201a: NOT optical observations
- GRB 241128A: Swift/UVOT Upper Limits
- EP241201a: Kinder optical counterpart candidate
- LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
- EP241126a: SOAR observations of the optical counterpart
- EP241126a: 1.6m Mephisto Optical Upper Limits
- LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
- GRB 241128A: AbAO optical upper limit
- EP241126a: NOT optical observations
- GRB 241127A: PRIME near-infrared detection
- GRB 241128A: Mondy optical observations
- GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
- Swift-XRT observations of IceCube -241127A
- EP241126a: SVOM/VT observations
- GRB 241128A: NOT optical observations
- GRB 241128A: LCO optical detection
- GRB 241128A: 1.5m OSN optical afterglow detection
- GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
- GRB 241127A: Swift/UVOT Detection
- GRB 241127A: SVOM/GRM observation
- GRB 241127A: LCOGT (40-cm) optical counterpart detection
- Swift GRB241127.91: Global MASTER-Net OT detection
- EP241126a: WFST Observations
- GRB 241127A: Swift detection of a burst with an optical counterpart
- Swift GRB241127.91: Global MASTER-Net OT detection
- EP241126a: Optical Upper limits with Kinder observations
- EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
- EP241126a: EP-FXT follow-up observation update
- EP241126a: GSP detects optical counterpart
- EP241126a: TRT optical counterpart detection
- LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on Optical Counterparts to Two of the Swift/XRT Sources
- 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
- LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
- GRB 241026A: radio detection with the VLA
- EP241125a: Optical upper limit with Kinder observations
- LIGO/Virgo/KAGRA S241125n: COLIBRÍ Upper Limits on a Optical Counterpart at the BAT Position
- LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
- GRB 241113B: SVOM/VT optical afterglow observations
- GRB 241105A: ATCA radio detection
- GRB 241026A: VIRT Optical Upper Limit
- GRB 241025A: VIRT Optical Upper Limit
- GRB241120A: OHP/T193 optical observations
- 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
- EP241119a: Optical upper limits with Kinder observations
- EP241119a: GIT optical upper limits
- GRB 241113A: Possible ATCA Radio detection
- GRB 241112B: Mephisto further optical observations
- GRB 241117A: SVOM/GRM observation of a short burst with extended emission
- EP241115a/GRB 241115D: Optical upper limits with Kinder observations
- GRB 241115A: Mephisto upper limits
- GRB 241113B: Mephisto upper limits
- GRB 241115D / EP 241115a: SVOM/GRM observation
- GRB 241115A: LCOGT Optical Upper Limits
- EP 241113a: LBT possible optical counterpart
- GRB 241113B: KAIT Optical Afterglow Candidate
- GRB 241113A: J-band observations with WINTER
- GRB 241030A: LCO optical observation
- GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
- GRB 241113A: KAIT optical observations
- GRB 241113B: SVOM/GRM observation
- EP241107a: SOAR upper limits
- GRB 241113A: REM detection of the optical/NIR afterglow
- GRB 241113A: LCO optical observations
- GRB 241112B: GMG Optical Upper Limit
- GRB241113A: LCOGT (40-cm) optical counterpart detection
- GRB 241113A: MASTER010615.66-224018.2 optical counterpart detection
- GRB 241113A: Swift detection of a burst with an optical counterpart
- SVOM/GRM detection of a short burst from SGR 1E1841-045
- GRB 241105A: ATCA Radio Upper Limits
- GRB 241112B: AbAO optical upper limit
- GRB 241107A: GROWTH-India telescope optical upper limit
- GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
- GRB 241112B: LCO optical detection of the SVOM/VT candidate
- GRB 241112B: SVOM/GRM observation
- GRB 241112B: SVOM/VT afterglow detection
- GRB 241112B: Mephisto optical upper limits