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"32531 results found.
- 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
- ANNOUNCEMENT ON INTEGRAL GRB ALERTS
- Distribution of INTEGRAL SPI-ACS triggers
- 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
- IPN triangulation of GRB030109 (annulus)
- IPN triangulation of GRB030105 (large error box)
- IPN triangulation of GRB030102B (refined localization - portion of annulus)
- Coronas-F -Wind triangulation of GRB030102
- IPN triangulation of GRB030102 (annulus)
- VLT spectroscopy of the probable host of GRB 021211
- GRB021226
- GRB 021211: Probable Host and Underlying Supernova
- GRB 021226 registration by Helicon/Coronas-F
- GRB 021112: Evidence for Another Dark Optical Afterglow
- GRB 021219: OSN optical observations
- GRB021219: Radio Observations
- GRB021219, optical 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
- GRB021211: APO optical observations
- IPN detection of continued activity from SGR1806-20
- 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
- GRB 021211: early break in light curve
- GRB021211, BVRI field photometry
- GRB021211: Optical observations in CrAO
- GRB 021211, IR observations
- GRB 021211, optical observations
- GRB 021211: Optical Observations
- GRB021211: Kiso Observations
- GRB 021201, optical observations
- GRB 021211: Radio Observations
- GRB021211: Optical observations
- GRB 021201 (short/hard), NOT observations
- SUB-MM SEARCH FOR GRB 021211
- Chandra observation of the IPN error box of GRB021201 (short/hard)
- GRB 021211, R- and I-band observations
- GRB021211 - Upper limits from recent and historical observations
- GRB021211, OT at 108 s
- GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
- HETE 2493: Optical observations
- GRB 021125: Radio Observations
- IPN triangulation of GRB021206 (small 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
- GRB021004, late time optical observations
- GRB021004 Chandra Observation
- GRB021125 refined position
- IPN triangulation of GRB021125B (two large error boxes)
- IPN triangulation of GRB021119 (large error box)
- Improved IPN error box for GRB021125
- IPN BURST POSITION
- IPN confirmation of the reactivation of SGR1900+14
- GRB021113, SPI ACS observation
- GRB 021112: Afterglow or Variable Star?
- GRB021113: optical observations at Bisei
- GRB 021113: Evidence for a Dark Optical Afterglow
- GRB 021112: Variable Source in R-band search
- GRB021112: Optical 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 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
- GRB021004: Near infrared spectroscopy
- GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
- Spectropolarimetry of GRB021004
- GRB021104: optical observations
- GRB021104: Candidate present in DSS
- 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)