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"5513 results found.
- GRB 060202: Gemini-N J, H, K_s observations
- GRB 060202: Near-IR Observation with UKIRT/WFCAM
- GRB 060121: I-band Limits
- GRB060121: SARA Observations
- GRB 060117: PROMPT Observations
- GRB 060116: PROMPT Observations
- GRB 060115: PROMPT Observations
- GRB 060114: Swift/UVOT Observations
- GRB 060115: MITSuME optical afterglow candidate
- GRB060111A: RTT150 optical observations
- GRB 060110: Optical limit
- Swift-BAT trigger 175653 is not an astrophysical source
- Swift-BAT trigger 175653 is probably not a GRB
- GRB 051227: MDM Observation
- Swift-BAT detection of a possible burst
- GRB 051221: Improved astrometry of the IR counterpart
- GRB051211b: P60 Observations
- Possible resuming of the SGR 1806-20 activity
- GRB 051117B,optical observation
- GRB 051111: Keck HIRES redshift
- GRB051111: Swift-BAT detection of a bright burst
- GRB051109B: no UVOT source detected
- GRB 051109B: Swift detection of a burst
- GRB 051109: HET Optical Spectrum and Absorption Redshift
- GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
- GRB051105B: Swift/XRT upper limit
- GRB051103: MASTER: OT limit and host galaxy candidates
- GRB051103:_MASTER_optical_observations
- GRB051028:MASTER observations
- GRB051021.63
- Swift-BAT trigger 160640 is not a real GRB
- GRB051021: A GRB Localized by HETE
- GRB050925: Swift UVOT upper limits
- GRB 050916: XRT position
- Swift is in normal operation
- GRB 050906: Possible X-ray Counterpart
- GRB 050906: Radio Observations
- GRB050904: Optical Observations
- Swift-BAT triggers 153461-153465 are not GRBs
- Retraction of Swift-BAT trigger #153355
- GRB050827: Swift-BAT detection of a burst
- GRB050822: Swift/UVOT upper limits
- GRB 050822: Swift-BAT refined analysis
- GRB 050822: ROTSE-III Prompt Optical Limits
- GRB 050822: Swift detection of a long burst
- GRB050820B: Planned XMM-Newton observation
- GRB050820B: BAT-Swift detection of a bright GRB
- GRB050813, SDSS pre-burst observations
- RBO GRB 050714A and GRB 050716 observations
- GRB050730: Radio Detection
- GRB 050730, corrected photometry and break?
- GRB050801: Swift-BAT detection of a burst
- GRB 050730, spectra and optical photometry
- GRB 050730: Swift XRT afterglow observations
- GRB050730, afterglow observations
- GRB 050730 : Planned XMM-Newton observation
- GRB050730: Liverpool Telescope optical observations
- GRB 050730, optical candidate
- GRB 050724, SMARTS optical/IR afterglow observations
- GRB050726: Swift-BAT detection of a weak burst
- GRB 050715: Swift-BAT detection
- Swift detection of a long transient (GRB 050714B?)
- GRB 050712: Swift XRT afterglow position
- GRB 050712: Swift detection of a weak burst
- GRB 050626: Swift XRT observations
- H11603: An X-ray flare from V4641 Sgr, or a possible XRF
- GRB 050626 - a long GRB detected with INTEGRAL
- GRB 050603: INTEGRAL shows it is not a short GRB
- GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
- GRB 050525: MITSuME Optical Observation in VRI
- GRB 050525A: BOOTES simultaneous optical observations
- GRB050525: Optical observations
- XRF 050522: Swift XRT refined analysis
- RBO Observations of GRB050520
- GRB 050505: SARA Observations
- GRB 050502a: Swift XRT Upper Limit
- GRB 050416: Swift/UVOT detection of afterglow emission
- GRB050416: Refined Swift-XRT analysis
- GRB 050416: Swift XRT Position
- GRB050416: P60 Afterglow Candidate
- GRB 050412: Subaru observations
- GRB 050412: optical limit
- GRB 050412: Swift-BAT refined analysis
- GRB 050412: Swift XRT Position
- Swift-BAT Detection of GRB 050412: A Bright, Long Burst
- GRB 050408, SMARTS optical/IR afterglow observations
- GRB 050408: Swift XRT Position
- GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
- GRB050401, radio observation at 4.8 GHz and 8.64 GHz
- GRB050331: No Afterglow Detected
- Swift-BAT detection of a bright outburst from SGR1806-20
- Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
- GRB 050318: Swift/UVOT detection of afterglow emission
- GRB 050318: Magellan optical afterglow identification
- GRB050318: Swift XRT position
- GRB050223: analysis of the XMM-Newton observation
- GRB050316: MASTER before, simultanious and follow up optical
- GRB 050306: ROTSE-III early limits
- GRB 050315, SMARTS optical/IR afterglow observations
- GRB050309: CONCAM pre-trigger and trigger coincident optical