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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"19091 results found.
- IPN Triangulation of GRB 150202B
- GRB 150203A: Swift-XRT refined Analysis
- GRB 150202B: Tiled Swift observations
- 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: Fermi GBM observation
- GRB 150203A: TAROT La Silla observatory optical observations
- GRB 150203A: GROND Upper limits
- GRB 150202B: Fermi-LAT detection
- GRB 150203A: Enhanced Swift-XRT position
- GRB 150203A: RATIR Optical and NIR Observations
- GRB 150202A: Enhanced Swift-XRT position
- GRB 150202A: GROND Upper limits
- GRB 150203A: Swift detection of a burst
- GRB 150202A: Swift detection of a burst
- GRB 150201A: Swift/UVOT Upper Limits
- GRB 150201A, Swift-BAT refined analysis
- GRB 150201A: GROND upper limits
- GRB 150201A: Fermi GBM observation
- GRB 150201A: Enhanced Swift-XRT position
- GRB 150201A: Swift detection of a burst
- GRB 150120B: Khureltogot optical observations
- GRB 150120A: 9.8 GHz VLA upper limit
- IPN Triangulation of GRB 150127B
- GRB 150120A: Gemini-N imaging and host redshift
- GRB 150127A: Fermi-LAT detection
- Swift Trigger 628458 likely not astrophysical
- GRB 150123A: Swift/UVOT observations
- GRB 150120B: Mondy optical observations
- Konus-Wind observation of GRB 150118B
- GRB 150120B: RATIR Optical and NIR Observations
- IPN Triangulation of GRB 150118B (long/intense)
- GRB 150120A: ISON-NM early optical limit
- GRB 150120B: Swift/UVOT Upper Limits
- GRB 150120B: GROND Afterglow Detection
- GRB 150101B: Confirmation of a fading optical counterpart
- GRB 150120B: MITSuME Okayama upper limits
- Konus-Wind observation of GRB 150118C
- GRB 150101B/Swift J123205.1-105602: TNG NIR follow-up
- GRB 150120A: Swift/UVOT Upper Limits
- GRB 150101B/Swift J123205.1-105602, deep VLT observations
- GRB 150120B: Enhanced Swift-XRT position
- GRB 150101B/Swift J123205.1-105602: XMM-Newton observation
- GRB 150120A: Enhanced Swift-XRT position
- GRB 150120B: P60 optical afterglow
- GRB 150120B: Swift detection of a burst
- GRB 150120A: Gemini-North optical imaging
- GRB 150120A: Swift detection of a possibly-short burst
- GRB 150101B/Swift J123205.1-105602: continued WSRT radio and VLT optical observations
- GRB 150118B: Fermi GBM Detection
- GRB 150118B: Fermi-LAT detection
- GRB 150110B: Khureltogot optical upper limit
- The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
- Swift detection of the variable star SZ Psc
- GRB 150110C: Swift/UVOT Upper Limits
- GRB 150110B: Swift-BAT refined analysis
- GRB 150110B: Swift/UVOT Upper Limits
- GRB 150110B: Fermi GBM Detection
- GRB 150110B: Enhanced Swift-XRT position
- GRB 150110A: Fermi GBM Detection
- GRB 150110B: Swift detection of a burst
- GRB 150101B/Swift J123205.1-105602: Chandra observations
- GRB 150101B / Swift J123205.1-105602: 9.8 GHz VLA observations
- Fermi GBM trigger 150108121 is not a GRB
- Swift detection of 4U 1700+24 (= V* V934 Her)
- GRB 150101B: Fermi GBM detection
- GRB 150103A: Swift/UVOT Upper Limits
- GRB 150103A: Zadko observatory - Gingin optical observations
- GRB 150103A: Enhanced Swift-XRT position
- GRB 150103A: Swift detection of a burst
- Swift J123205.1-105602: XRT and UVOT observations of soft short burst source
- Short burst found in ground analysis of Swift-BAT data
- GRB 150101A: Swift/UVOT Upper Limits
- GRB 150101A: Enhanced Swift-XRT position
- GRB 150101A: Swift detection of a short burst
- Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
- GRB 141229A Swift-BAT observations
- GRB 141230A: Nanshan optical obsrvations
- GRB 141229A: 1.23m CAHA optical observations
- GRB 141229A: Nanshan optical upper limit
- Christmas GRB 141225A: GROND Observations
- GRB 141225A: MITSuME Okayama upper limits
- GRB 141225A: TAROT Calern observatory optical observations
- GRB 141225A: Swift/UVOT refined analysis
- GRB 141225A: very early T60 observations
- GRB 141225A: Swift-BAT refined analysis
- GRB 141225A: Nanshan very early optical observations
- GRB 141225A: Enhanced Swift-XRT position
- GRB 141225A: Optical aftergow confirmation
- GRB 141225A: 1.23m CAHA optical observations
- GRB 141225A: Swift detection of a burst
- GRB 141221A: TAROT La Silla observatory optical observations
- Swift XRT and UVOT observations of GRB141222A
- GRB 141221A: MITSuME Akeno upper limits
- GRB 141221A: Continued Skynet PROMPT-CTIO observations
- GRB 141221A: Swift/UVOT Detection
- GRB 141215A: further Swift-XRT observations and afterglow detection
- GRB 141221A: Fermi GBM observation