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"35353 results found.
- IPN triangulation of GRB030115C (large error box)
- GRB030115: R-band counterpart of IR candidate
- GRB030115, afterglow candidate
- GRB 021211: R-band observations at late-time
- GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
- IPN triangulation of GRB030115B (small error box)
- GRB 030115 : Possible IR counterpart
- GRB 030115: Radio Observations
- GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
- Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
- IPN triangulation of GRB030115B (annulus)
- ANNOUNCEMENT ON INTEGRAL GRB ALERTS
- Distribution of INTEGRAL SPI-ACS triggers
- GRB030115: R-band observations at Asiago
- GRB030115: TAROT optical observations
- GRB 021211: VLT spectrum
- GRB 030115: APO Optical Observations
- GRB 030115, no optical candidate
- GRB 030115, optical observations
- GRB 030115, optical candidate
- Possible GRB030113 seen by SPI ACS
- Probable GRB030112B seen by SPI ACS
- Probable GRB030112 seen by SPI ACS
- Possible GRB030111 seen by SPI ACS
- Possible GRB030110b seen by SPI ACS
- Possible GRB 030110 seen by SPI ACS
- IPN triangulation of GRB030109 (annulus)
- IPN triangulation of GRB030105 (large error box)
- IPN triangulation of GRB030102B (refined localization - portion of annulus)
- Possible GRB 20030109 seen by SPI ACS
- IPN triangulation of GRB030102B (portion of annulus)
- IPN triangulation of GRB030102A (large error box)
- Possible GRB20030107 seen by SPI-ACS
- Possible GRB 20030105 seen by SPI ACS
- IPN triangulation of GRB030102 (annulus)
- GRB on 20030102 seen by SPI-ACS
- VLT spectroscopy of the probable host of GRB 021211
- GRB on 20030101 seen by SPI-ACS
- IPN triangulation of GRB030101 (two large error boxes)
- GRB021226
- GRB 021211: Probable Host and Underlying Supernova
- GRB 021226 registration by Helicon/Coronas-F
- Probable GRB in INTEGRAL SPI-ACS
- IPN triangulation of GRB021223 (two large error boxes)
- GRB021211, radio observations
- GRB 021112: Evidence for Another Dark Optical Afterglow
- GRB 021219: OSN optical observations
- GRB021219: Radio Observations
- IPN triangulation of GRB021219 - CORRECTION
- IPN triangulation of GRB021219
- GRB021219, optical observation by MASTER
- GRB021219: Correction to GCN 1766
- VLT spectra of GRB 021211 revisited
- GRB021219: a long GRB localized by INTEGRAL
- IPN detection of continued activity from SGR1806-20
- IPN triangulation of GRB021215 (large error box)
- IPN triangulation of GRB021214 (annulus)
- XRF 020903 : HST observations
- GRB 021201: Optical Observations
- GRB 021211, optical observations
- GRB 021211: CTIO observations
- GRB021211: Measurement of Early Time Afterglow
- VLT spectrum of GRB 021211
- IPN triangulation of GRB021211B (two large error boxes)
- GRB 021211: early break in light curve
- GRB021211, BVRI field photometry
- GRB 021211, IR observations
- GRB 021211, optical observations
- GRB 021211: Optical Observations
- GRB021211: Kiso Observations
- GRB021204: Kiso Observations
- GRB 021201, optical observations
- GRB 021211: Radio Observations
- GRB 021201 (short/hard), NOT observations
- SUB-MM SEARCH FOR GRB 021211
- GRB 021211 Milagro GeV/TeV Observations
- GRB 021211, R- and I-band observations
- GRB021211 - Upper limits from recent and historical observations
- GRB 021204: I-band Observations
- GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
- HETE 2493: Optical observations
- GRB 021204: Optical Observations at RIKEN
- GRB 021125: Radio Observations
- IPN triangulation of GRB021206 (small error box)
- IPN triangulation of GRB021206 (exceptionally bright; annulus only)
- IPN detection of renewed activity from SGR1806-20
- IPN triangulation of GRB021205 (large error box)
- GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
- GRB021201, BVRcIc field photometry
- GRB 021201, Radio Observations
- GRB 021201: Optical Observations
- 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
- IPN triangulation of GRB021115 (annulus)
- IPN triangulation of GRB021125B (two large error boxes)
- IPN triangulation of GRB021119 (large error box)