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"45645 results found.
- GRB 060108: Refined XRT analysis
- GRB 060108: VLT J-band observations
- GRB 060108: Mitsume optical observations
- GRB 060108: Swift/UVOT upper limits
- GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
- GRB060108: SDSS pre-burst observations
- GRB060108: Faulkes Telescope observation
- GRB060108, optical observation
- GRB 060108: Refined analysis of the Swift-BAT burst
- GRB 060108: Swift XRT position
- GRB060108: Swift detection of its 100th GRB
- GRB 060105: pseudo-z from spectral parameters of the prompt emission
- GRB 060105: Radio observations
- GRB 060105: MDM Observation
- Konus-Wind observation of GRB 060105
- GRB 060105: ISAS observations and near IR upper limit
- GRB 060105: Swift/UVOT upper limits
- GRB 060105: Mitsume optical observations
- GRB 060105: BAT refined analysis
- GRB 060102 - no XRT afterglow
- GRB 060105: XRT refined analysis
- GRB060105: Suzaku-XIS and -HXD observation plan
- GRB060105, optical observation
- GRB060105 : Kiso optical observation
- GRB060105: Swift detection of a bright long burst
- Swift-BAT trigger 175653 is not an astrophysical source
- GRB 060102: MDM Observation
- Swift-BAT trigger 175653 is probably not a GRB
- GRB 060102: Swift-BAT refined analysis
- Time Correction to GRB 060102
- GRB 060102: Swift-BAT detection of a burst
- GRB051211B: optical observations
- GRB051227: SARA Observations
- GRB 051221B: Optical Observations with Kuiper 1.54m
- GRB 051227: Likely host galaxy underlying afterglow position
- GRB 051227: optical observation
- GRB051221B: Radio observations
- GRB 051221A: VLA Radio Observations
- GRB051227: Radio Observations
- GRB 051227: Confirmed fading from Gemini observations
- GRB051227: further analysis of VLT images
- GRB 051227: optical afterglow
- GRB 051227: Swift/UVOT Upper Limits (Possible U-band
- GRB 051227: Gemini observations
- GRB 051227: Keck Spectroscopy
- GRB 051227: Magellan r'-band Imaging/Astrometry
- GRB 051227: refined analysis of VLT images
- GRB 051227: P60 Observations
- GRB 051227: MDM Observation
- GRB 051227: R-band object in the XRT error circle
- GRB 051227: Joint Swift-HETE Spectral Analysis
- GRB 051227: XRT refined analysis
- GRB 051227: Further analysis of the Swift-BAT burst
- GRB 051227: Refined analysis of the Swift-BAT burst
- GRB051227: SDSS pre-burst observations
- GRB 051227, optical observation
- GRB 051227: Swift detection of a burst
- GRB051117B: optical observation
- IBAS_alert n. 2719 : not a real GRB
- Konus-Wind observation of GRB 051221A
- GRB051221A: Suzaku WAM observation of the prompt emission
- GRB 051221A: MDM Optical Observations
- GRB051016: analysis of the XMM-Newton observation
- GRB 051221A: Detection at 251nm with Swift UVOT
- GRB 051221A: Chandra Afterglow Position
- GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
- GRB 051221B: ROTSE-III Optical Limits
- GRB 051221B: TAROT optical limits
- GRB 051221A: WSRT Radio Observations
- GRB 051221: Redshift from Gemini
- GRB 051221: Continued fading of optical afterglow
- GRB 051221B: Refined analysis of the Swift-BAT burst
- Possible GRB 051221B: MDM Optical Detection
- GRB 051221A: RAPTOR Fading Counterpart Constraint
- GRB 051221B: BOOTES optical observations.
- Possible GRB 051221B: Swift XRT position
- GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral
- Swift-BAT detection of a possible burst
- GRB 051221: Discovery of fading optical afterglow
- GRB 051221: Swift XRT refined analysis
- GRB 051221: Swift/UVOT upper limits
- GRB 051221: Possible nearby cluster
- GRB 051221: No variability in Gemini data
- GRB 051221: Correction to GCN #4368
- GRB 051221: Gemini observations
- GRB 051221: Improved astrometry of the IR counterpart
- GRB051221: K-band source
- GRB 051221: XRT position
- GRB 051221: Refined analysis of the Swift-BAT short hard burst
- GRB 051221: IR Observations at GRB+1hr
- GRB 051221: Swift detection of a bright short burst
- Refined analysis of the SWIFT J1626.6-5156
- Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
- Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
- GRB051211A (=H3979): Refined Analysis
- GRB 051211B: optical afterglow
- Swift detection of an RS CVn flare star
- GRB051211A: possible optical candidate
- Swift Trigger 172767 is not a GRB
- GRB 051215: near-infrared observations