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"15251 results found.
- Swift Trigger #152652 is not a GRB
- GRB 050827: Optical Limit
- Subaru Observations of GRB050724
- GRB050824, HETE-2 Observation
- GRB 050826: BAT refined analysis
- GRB 050826: Swift XRT position
- Swift-BAT trigger 152038 is definitely not a GRB
- GRB050824: CORRECTION to UVOT observing times
- GRB050824: Swift/UVOT detection of fading afterglow
- GRB050824, I-band imaging
- GRB 050822: refined XRT analysis
- GRB 050824: BAT refined analysis of a soft weak burst
- GRB050820a: PROMPT RcIc Observations
- XRF050509c: Radio upper limits from GMRT
- VLT/UVES spectroscopy of GRB050820
- GRB 050820A BAT observations of second, larger episode of emission
- GRB 050822: Swift-BAT refined analysis
- GRB 050820a - corrections to GCN 3846
- Correction to Eiso calculation in GCN 3835 on GRB 050820A
- GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
- GRB 050820a: NIR Observations by WIRO
- GRB 050820B: Swift XRT position
- GRB050820: refined XRT analysis
- GRB 050820: Early RAPTOR detections
- GRB 050820 Swift-BAT refined analysis
- GRB 050820: High Resolution Spectroscopy from Keck
- GRB050819: refined XRT analysis
- GRB 050819 Swift-BAT refined analysis
- GRB050819: Swift XRT position
- GRB050817: Negative Optical Observations
- GRB050815: Swift-BAT detection of a burst
- GRB050814: Fading red source
- GRB 050813: Gemini Spectra Revisited
- GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
- GRB 050814: Swift XRT Afterglow Localization
- GRB 050813: Magellan detection of a high redshift galaxy cluster
- GRB050813, SDSS pre-burst observations
- GRB 050813: KAIT optical limit
- GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
- GRB050803: CrAO optical observations, no OT candidate
- GRB050805a : Null detection report
- GRB050802: TNG optical observations
- GRB050803: Optical/UV Upper Limits from Swift-UVOT
- GRB 050802.422: Fading of the afterglow and detection of the host
- GRB 050803, optical observations
- GRB 050803: early Swift XRT analysis results
- GCN GRB observation 050713A
- GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
- GRB 050802: Swift/UVOT optical and UV detections
- GRB050802 radio non-detection
- GRB 050802: early Swift XRT analysis results
- GRB050801: Optical photometry and decay index
- GRB 050802: XRT position
- GCN 050801: early Swift XRT analysis results
- GRB 050801, afterglow observations
- GRB 050730, corrected photometry and break?
- GRB 050801: ROTSE-III Early Afterglow Break
- GRB 050730: XRT refined analysis
- GRB050730, afterglow observations
- GRB050730: confirmation of redshift
- GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
- GRB 050724: Secure Host Redshift from Keck
- GRB 050724: Chandra Observations of the X-ray Afterglow
- GRB050713: analysis of the XMM-Newton observation
- GRB 050726, SMARTS optical/IR observations
- GRB050724: VLT observations of the variable source
- GRB050709: Second Epoch Chandra Observation
- GRB050709: Second Epoch Chandra Observation
- GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
- GRB 050726: early Swift XRT analysis results
- GRB050726: Swift-BAT detection of a weak burst
- GRB 050724: J-band observations
- RXTE ASM Detection of GRB050724
- GRB 050724: Optical imaging/astrometry
- GRB 050724: RTT150 optical observations
- GRB 050724 : Lulin early R-band monitoring observations
- GRB050724: Refined analysis of the Swift-BAT possible short burst
- GRB050724: a short-burst detected by Swift
- GRB 050721A: Swift-BAT refined analysis
- Correction to GCN Circ 3474 on GRB050525A
- GRB 050721: optical afterglow confirmed
- GRB 050721a: Optical Observations
- GRB050721A: Swift-BAT detection of a weak burst
- GRB 050709: Refined Spectral and Temporal Properties
- Swift-BAT trigger 146731 is not a real GRB
- Swift-BAT detection of a possible GRB
- GRB 050714B: VLT R-band observations
- GRB 050716; J-band observations
- Konus-Wind observation of GRB 050717
- GRB 050717: Refined XRT analysis.
- GRB050717: Swift XRT position
- GRB 050716 - UKIRT identification of candidate afterglow
- GRB 050716: Refined XRT analysis.
- GRB050716: Correction to sign in XRT coordinate
- Swift UVOT Observations of GRB 050714B
- Konus-Wind observation of GRB 050713A
- GRB 050714B: refined XRT analysis
- GRB 050714B: candidate afterglow does not fade
- GRB 050714: Swift XRT afterglow position
- GRB 050713A: XRT refined analysis