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"44441 results found.
- 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
- GRB021211: Optical observations in CrAO
- 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
- 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 Milagro GeV/TeV Observations
- GRB 021211, R- and I-band observations
- GRB021211 - Upper limits from recent and historical observations
- GRB021211, OT at 108 s
- GRB021211 (HETE2493), OT at 143 sec
- GRB 021204: I-band Observations
- GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
- HETE 2493: Optical observations
- HETE 2493: Optical candidate
- 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
- 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 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
- 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