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"- GRB 021201: BOOTES simultaneous optical observations
- IPN triangulation of GRB021201 (short/hard burst, small error box)
- Radio Catalog of GRB Afterglows
- GRB021004, late time optical observations
- GRB021004 Chandra Observation
- IPN detection of continued SGR1900+14 activity
- GRB021125 refined position
- IPN triangulation of GRB021115 (annulus)
- IPN triangulation of GRB021125B (two large error boxes)
- IPN triangulation of GRB021119 (large error box)
- IPN triangulation of GRB021125B (annulus)
- Improved IPN error box for GRB021125
- IPN BURST POSITION
- IPN triangulation of GRB021125 (INTEGRAL BURST)
- GRB021125 : A long GRB localized by INTEGRAL
- IPN confirmation of the reactivation of SGR1900+14
- IPN detection of possible reactivation of SGR1900+14
- GRB021113, SPI ACS observation
- IPN triangulation of GRB021119 (annulus)
- GRB 021112: Afterglow or Variable Star?
- GRB021113: optical observations at Bisei
- GRB 021113: Evidence for a Dark Optical Afterglow
- GRB 021112, Radio Observations
- GRB021112, BVRI field photometry
- GRB 021112: Variable Source in R-band search
- GRB021112: Optical Observations
- GRB021113: Kiso Observations
- IPN triangulation of GRB021109 (portion of annulus)
- IPN triangulation of GRB021113 (=H2449; annulus)
- IPN triangulation of GRB021108 (CORRECTION; TWO LARGE ERROR BOXES)
- GRB 021113: Optical observations
- GRB 021112: RAPTOR Observations
- GRB 021113: Optical Observations
- GRB 021113: Optical Observations
- GRB021113 (=H2449): A Long GRB Localized by HETE
- GRB 021112: Optical Observations
- GRB 021112: R-band search
- IPN triangulation of GRB021108 (large error box)
- GRB021112 (=H2448): A Long GRB Localized by HETE
- GRB 021016: Optical Observations
- IPN triangulation of GRB021109 (annulus)
- IPN triangulation of GRB021108 (annulus)
- GRB021004: Near infrared spectroscopy
- GRB021104: Optical Observations
- IPN triangulation of GRB021104 (annulus)
- GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
- IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
- SGR1900+14 activity, November 2-4, 2002
- Spectropolarimetry of GRB021004
- GRB021104: Optical observations
- GRB021104: optical observations
- GRB021104: Candidate present in DSS
- GRB021104: possible optical afterglow
- IPN triangulation of GRB021102 (annulus)
- Detection of activity from SGR 1900+14 with the RXTE/PCA
- IPN triangulation of a burst from SGR1900+14 on November 01, 2002
- IPN triangulation of a burst from SGR1900+14 on October 29 2002
- IPN triangulation of GRB021025 (portion of annulus)
- IPN triangulation of GRB021027 (single large error box)
- GRB021004, late-time optical observations
- IPN triangulation of GRB021027 (two large error boxes)
- GRB 021023: Infrared Imaging
- IPN triangulation of GRB021027 (annulus)
- GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
- IPN triangulation of GRB021025 (annulus)
- IPN triangulation of SGR1900+14, October 22 2002
- GRB 021004: optical observations
- IPN triangulation of GRB021023 (small error boc)
- GRB021004: Optical Observations
- GRB 020813; likely host galaxy.
- IPN triangulation of GRB021020 (smaller error box)
- GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
- IPN triangulation of GRB021020
- GRB 021008, radio observations
- GRB 021016, optical observations
- GRB 021004: VRI observations at TNG: possible break
- GRB021016, optical observations
- SGR1900+14: burst on October 10 2002
- GRB 021008, optical observations
- GRB021016(=H2397): A Long GRB Localized by HETE
- IPN triangulation of GRB021016 (area corrected)
- IPN triangulation of GRB021016 (small error box)
- GRB021004: Optical Observations
- IPN triangulation of GRB021014 (large error box)
- IPN triangulation of GRB021013 (single error box)
- GRB 021004: optical spectroscopy on Oct 11
- IPN triangulation of GRB021013 (two small error boxes)
- GRB021004: High-resolution optical spectroscopy
- IPN triangulation of GRB021013 (annulus)
- XRF 020903: flattening of the optical light curve.
- GRB021004, UBVRcIc field photometry update
- IPN triangulation of GRB021008 (single error box)
- GRB021004: Optical Observations
- GRB 021004 submm observations
- IPN triangulation of GRB021008B (annulus)
- IPN triangulation of GRB021008 (two small error boxes)
- GRB021004 Chandra HETG Observations
- GRB 021004: Optical/NIR Observations
- GRB 021004: Additional V-band Polarimetric Observations
- GRB021004: optical observation