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"5050 results found.
- GRB 040624 - A long GRB detected with INTEGRAL
- IPN Summary of SGR1806-20 Activity in 2004
- SGR 1806-20, potential NIR counterpart
- GRB 040403: Optical Observations
- GRB 040403: Optical observations
- Summary of recent bursts from SGR 1806-20 detected by INTEGRAL
- GRB040323: NIR Observations and Variable Object
- GRB 040323, a dark GRB ?
- GRB040223: Deep NIR NTT data re-analysis
- IBAS results on a burst from SGR1806-20
- GRB 040228 Optical observations
- GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM
- GRB 040223: REM IJK Observations
- GRB031220: 2nd Chandra observation and X-ray afterglow candidate
- GRB 031220: Optical observations of Chandra X-ray sources
- GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
- GRB031220(=H2976): Observation with the Chandra X-ray Observatory
- IPN triangulation of GRB031219 (large error box)
- GRB031220: Palomar Observations
- IPN triangulation of GRB031201 (large error box)
- IPN triangulation of GRB031111 (=H2924): small error box
- IPN triangulation of GRB031108 (large error box)
- IPN triangulation of GRB031026B (large error box)
- IPN triangulation of GRB030922B (large error box)
- XRF 030723: Detection of the likely host galaxy
- XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
- GRB030913: Subaru Optical Observations
- GRB030913: AAVSO optical observations
- GRB 030913: Optical limit at RIKEN
- XRF030824: Optical observations
- INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
- XRF030824: optical observations
- XRF030723: optical observations
- H2768, H2770, and H2771: Three Bursts from SGR1806-20
- IPN triangulation of GRB030715 (two large error boxes)
- GRB030329: second XMM-Newton observation
- GRB030528(=H2724): Observations with the Chandra X-ray Observatory
- GRB 030329: optical observations
- GRB 030329: optical photometry at Belesta observatory (France)
- GRB030329, Optical observations
- GRB030329: XMM-Newton observation
- GRB030324: Further Observations of the Candidate Optical Afterglow
- GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
- GRB 030418: Second Epoch Optical Observations with Magellan
- GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
- GRB 030429: confirmation of afterglow candidate
- GRB030329, SPM optical observations
- GRB 030329, the review of the sky area in plate archive (1950-1998)
- GRB 030329: Spectral Evolution of SN 2003dh
- GRB030329: VR Photometry at TNG
- GRB030324: Candidate Optical Afterglow
- IPN triangulation of GRB050403 (small error box)
- GRB030329: final R-band light curve by MASTER
- GRB 030329, BRI photometry
- GRB 030329: Additional Mt. Laguna Optical Observations
- GRB 030329: Correction to GCN 2056
- GRB 030329: fitting parameters and re-brightening
- GRB 030329: optical observations
- GRB 030324, optical search
- GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
- GRB030324 optical observation
- Possible GRB030323 localized by INTEGRAL
- GRB030323: Detection on 2003/03/24
- IPN triangulation of GRB030325 (single small error box)
- GRB030324, optical observations
- GRB030324, optical observations
- GRB030324, Optical Observations
- GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
- GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
- VLT/FORS2 spectra of GRB 030323
- GRB030323, ROTSE-III detection of possible optical counterpart
- GRB030323, optical observations
- IPN triangulation of GRB030320
- GRB 030227: Optical limit at RIKEN
- GRB 030227: Optical observations
- GRB030227: Kiso optical upper limit
- GRB 030226: Steep Decline
- GRB030226: Candidate optical afterglow
- IPN triangulation of GRB030208 (annulus)
- GRB 030131: afterglow candidate
- GRB 030115, simultaneous observations by BOOTES-1
- IPN triangulation of GRB030101 (two large error boxes)
- GRB 021211: Probable Host and Underlying Supernova
- IPN triangulation of GRB021219 - CORRECTION
- GRB 021211: CTIO observations
- GRB 021211: Optical Observations
- Chandra observation of the IPN error box of GRB021201 (short/hard)
- IPN detection of continued SGR1900+14 activity
- GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
- GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
- IPN triangulation of GRB021023 (small error boc)
- IPN triangulation of GRB021013 (single error box)
- IPN triangulation of GRB021013 (two small error boxes)
- GRB021004: NIR and Optical observations
- GRB021004: BVRc photometry
- GRB021004, Optical Observations
- GRB 021004: Optical Photometry at 1.5 Days
- GRB 021004, SPM optical observations
- GRB 021004: steepening of the optical decay slope
- GRB021004: Upper limits from recent and historical observations