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"12321 results found.
- GRB 150301A: Swift/UVOT Upper Limits
- GRB 150301B: MASTER early OT detection
- GRB 150301C : (Swift trigger 633105) Swift observations
- Swift Trigger 633173 is probably not an astrophysical source
- Trigger 633105 is likely not a GRB
- Trigger 632888: Swift detection of the magnetar 4U 0142+61
- GRB 150220A: Swift-XRT observations
- Konus-Wind observation of GRB 150220A
- GRB 150222A: Swift/UVOT Upper Limits
- GRB 150222B: MAXI/GSC detection
- GRB 150222A: MASTER early optical observations
- GRB 150222A: Swift detection of a burst
- Swift detection of an outburst from SGR 1935+2154
- Trigger 631747: Swift detection of 4U 0614+09
- GRB 150213B: Swift/UVOT Detection
- GRB 150213B: RATIR Optical and NIR Observations
- GRB 150211A: ROTSE-III Upper Optical Limit
- GRB 150212A: RATIR Optical and NIR Observations
- GRB 150212A: Khureltogot optical upper limit
- GRB 150212A: MASTER optical observations
- GRB 150210A: Swift-XRT observations
- GRB 150211A iTelescope observation
- GRB 150211A: Swift/UVOT Upper Limits
- GRB 150210A: MASTER SN detection during LAT error box inspection
- GRB 150211A: KAIT Optical Upper Limit
- GRB 150211A: Mondy optical upper limit
- Konus-Wind observation of GRB 150210A
- GRB 150211A: RATIR Optical and NIR Observations
- GRB 150211A: No afterglow detection in the Swift/UVOT initial observation
- GRB 150211A: MASTER early optical observations
- GRB 150204A: GROND observations
- GRB 150202B: Swift/XRT afterglow confirmation
- GRB 150204A: Swift/XRT afterglow confirmation
- GRB 150203A iTelescope observation
- GRB 150206A: Swift/UVOT Detection
- GRB 150206A: GROND afterglow observations
- GRB 150206A: MAXI/GSC detection
- GRB 150204A: Swift/UVOT Upper Limits
- GRB 150204A: Swift-XRT observations
- GRB 150202B: Swift XRT/UVOT observations
- Swift Trigger 629693 was a noise event
- GRB 150203A: Swift/UVOT Upper Limits
- GRB 150203A: MITSuME Okayama upper limits
- Swift Trigger 629693: probably not real
- GRB 150202A: Swift/UVOT Upper Limits
- GRB 150203A: REM optical and NIR observations
- GRB 150203A: GROND Upper limits
- GRB 150203A: RATIR Optical and NIR Observations
- GRB 150202A: GROND Upper limits
- GRB 150203A: KAIT Optical Upper Limit
- GRB 150203A: Swift detection of a burst
- GRB 150202A: Swift detection of a burst
- GRB 150201A: Swift/UVOT Upper Limits
- GRB 150201A: GROND upper limits
- GRB 150201A: Swift detection of a burst
- GRB 150128A: MASTER OT detction during inspection
- Konus-Wind observation of GRB 150127B
- GRB 150123A: MASTER inspection
- GRB 150120A: 9.8 GHz VLA upper limit
- Konus-Wind observation of GRB 150126A reveals its ultra-long nature
- Swift Trigger 628458 likely not astrophysical
- GRB 150126A: MAXI/GSC afterglow candidate detection
- GRB 150120A: possible AMI 15 GHz detection
- GRB 150123A: Swift/UVOT observations
- GRB 150123A: MAXI/GSC detection
- Konus-Wind observation of GRB 150118B
- GRB 150120B: RATIR Optical and NIR Observations
- GRB 150120B: Swift/UVOT Upper Limits
- GRB 150120B: GROND Afterglow Detection
- GRB 150120A: KAIT Optical Upper Limit
- GRB 150120B: MITSuME Okayama upper limits
- Konus-Wind observation of GRB 150118C
- GRB 150120A: Swift/UVOT Upper Limits
- GRB 150110B: AMI 15 GHz detection of possible radio counterpart
- GRB 150120A: Swift detection of a possibly-short burst
- GRB 150110B: Khureltogot optical upper limit
- GRB 150110C: Swift/UVOT Upper Limits
- GRB 150110A: MASTER inspection
- GRB 150110B: Swift/UVOT Upper Limits
- GRB 150110C: MAXI/GSC detection
- GRB 150110B: Swift detection of a burst
- GRB 150110A: MAXI/GSC detection
- Radio upper limit on the GRB 141121A with the GMRT
- GRB 150103A: MASTER optical observations
- GRB 150103A: Swift/UVOT Upper Limits
- GRB 150103A: Swift detection of a burst
- GRB 150101A: Swift/UVOT Upper Limits
- GRB 150101A: Swift detection of a short burst
- Konus-Wind observation of GRB 141229A
- GRB 141229A: Deep MASTER inspection
- Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
- GRB 141229A: Nanshan optical upper limit
- GRB 141225A: MITSuME Okayama upper limits
- GRB 141225A: Swift/UVOT refined analysis
- Swift XRT and UVOT observations of GRB141222A
- Konus-Wind observation of GRB 141222A
- GRB 141221A: MITSuME Akeno upper limits
- GRB 141221A: Swift/UVOT Detection
- GRB 141215A: further Swift-XRT observations and afterglow detection
- GRB 141220A: MITSuME Akeno upper limits