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"11503 results found.
- GRB021211, OT at 108 s
- GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
- HETE 2493: Optical observations
- IPN triangulation of GRB021206 (exceptionally bright; annulus only)
- IPN detection of renewed activity from SGR1806-20
- GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
- Improved IPN error box for GRB021125
- GRB021125 : A long GRB localized by INTEGRAL
- IPN confirmation of the reactivation of SGR1900+14
- IPN triangulation of GRB021119 (annulus)
- GRB021112: Optical Observations
- GRB021113 (=H2449): A Long GRB Localized by HETE
- GRB021112 (=H2448): A Long GRB Localized by HETE
- GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
- GRB 021004: optical observations
- IPN triangulation of GRB021020 (smaller error box)
- GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
- IPN triangulation of GRB021020
- GRB 021016, optical observations
- GRB 021004: VRI observations at TNG: possible break
- GRB 021008, optical observations
- GRB021016(=H2397): A Long GRB Localized by HETE
- GRB021004: NIR and Optical observations
- GRB 021004: Optical measurement at OHP
- GRB 021004: optical spectroscopy
- GRB021004: BVRc photometry
- GRB 021004: Optical Photometry at 2.5 Days
- GRB 021004 radio observation
- GRB 021004: Optical Observations
- GRB 021004: Optical Photometry at 1.5 Days
- GRB021004, Optical Observations
- GRB 021004, optical observations
- GRB 021004, SPM optical observations
- GRB 021004: steepening of the optical decay slope
- XRF020903, BVRI field photometry
- GRB 020903: Optical observations at RIKEN
- XRF 020903: Supernova
- IPN triangulation of GRB020926 (two large error boxes)
- GRB020924 (ecliptic latitude-only localization)
- IPN triangulation of GRB020923 (two error boxes)
- Improved IPN position for GRB020918 (two large error boxes)
- IPN triangulation of GRB020911 (2 large error boxes)
- INTEGRAL GRBs added to GCN
- GRB020812: optical observation
- Second epoch K band imaging of GRB 020819
- GRB 020812: early time optical observation at Ouda Station
- GRB020813: Magellan BVRI Photometry
- GRB 020819 : OT candidate - confirmation of non variability
- K band observation of GRB 020819
- GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
- IPN triangulation of GRB020819 (HETE 2275)
- GRB020813: Fading X-ray Afterglow Observed with Chandra
- GRB020812: NIR observations
- GRB020812: optical observations
- GRB 020812 : optical afterglow candidate
- GRB020813, optical observations
- GRB 020812 optical observation
- GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
- GRB020801: Imaging of Suggested OT Counterpart at the Magellan
- GRB020801, optical afterglow candidate
- IPN triangulation of GRB020714
- GRB 020410: Discovery of Probable OT by HST
- Correction to IPN error box for GRB020706
- IPN triangulation of GRB020706
- GRB 020705: Optical observations
- GRB020625 (=H2081): A Long Burst Localized by HETE
- AXP 1E2259+586 optical observations
- SGR-like Bursts from the AXP 1E 2259+586
- GRB 020531, simultaneous optical observations
- GRB020531: Second epoch Chandra observations
- GRB020531: Observations with the Chandra X-ray Observatory
- GRB020531, optical observation
- IPN triangulation of the short, hard GRB020531 (=H2042)
- GRB020525, optical observations
- IPN detection of possible bursts from SGR1806-20
- IPN triangulation of GRB020525
- HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
- IPN triangulation of a burst from SGR1806-20
- GRB 020410, Radio Observations
- GRB 020124: Optical observations
- IPN triangulation of GRB020418
- GRB020410: BeppoSAX NFI observations refined analysis
- IPN triangulation of GRB020413
- GRB 020409 SARA Observations
- GRB 020409, No Optical Detection to R = 20
- GRB020410: BeppoSAX NFI observation
- GRB 020409, optical observations
- GRB020406(?), optical observations
- BeppoSAX ALERT: possible GRB020410
- GRB020331 optical observations with RIMOTS
- GRB020124 optical observations with RIBOTS/RIMOTS
- GRB 020321: Candidate X-ray Counterparts
- GRB020406(?), optical observations
- GRB 020331, NIR observations
- GRB020331(=H1963): The "Easter" Burst Detected by HETE
- GRB 020321: Optical observations
- GRB020317: optical observations
- GRB 020317 : KISO Optical Observations
- BeppoSAX ALERT: GRB020321, the "Springtime Burst"
- GRB 020317: Optical observations