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"- GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
- IPN triangulation of GRB030519 (annulus)
- IPN triangulation of GRB030518C (annulus)
- IPN triangulation of GRB030518B (annulus)
- IPN triangulation of GRB030518A (annulus)
- IPN triangulation of GRB030514 (annulus)
- HETE GRB030329, correction to Rc Observations in Loiano
- IPN triangulation of GRB030513 (annulus)
- IPN triangulation of GRB030509B (annulus)
- GRB 030329: Optical limit (contemporaneous imaging)
- GRB 030501: final TAROT limits
- IPN triangulation of GRB030509 (small errror box)
- IPN triangulation of GRB030509 - correction
- IPN triangulation of GRB030509 (single error box)
- GRB030329: RTT150 optical observations
- GRB030329, BVRI photometry
- GRB030429, refiend optical brightness
- GRB 030329: Optical limit (contemporaneous photography)
- GRB030418, BVRcIc field photometry
- GRB 030429: Redshift of neighbor galaxy
- GRB030429, BVRcIc field photometry
- GRB030429: RTT150 optical obs., correction to GCN 2208
- GRB 030329: High-Resolution Spectroscopy of the Host
- GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
- GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
- XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
- GRB030429: RTT150 optical observations, a possible host galaxy
- IPN triangulation of GRB030506 (annulus)
- IPN triangulation of GRB030505B (large error box)
- IPN triangulation of GRB030505A (annulus)
- GRB030329: RTT150 optical observations and upper limit for a host
- GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
- GRB030501, optical observation
- GRB030501 observation report
- GRB030501C triangulation (annulus)
- GRB030501 triangulation (correction to GCN 2194)
- GRB030329: RTT150 optical observations and upper limit for a host
- GRB 030429: Radio Observations
- GRB 030429: redshift from VLT spectroscopy
- GRB 030429: IR photometry with IRSF/SIRIUS
- GRB030501B triangulation (single error box)
- GRB 030329 Optical Observations
- GRB030328, optical observation
- GRB 030329, BVRI photometry
- GRB030429: Optical Observations
- GRB030501: TAROT candidate afterglow present in archival images
- GRB 030501: TAROT possible candidate counterpart
- IPN triangulation of GRB030501 (IBIS event; annulus)
- IPN triangulation of GRB030501B (annulus)
- GRB 030429: confirmation of afterglow candidate
- GRB030429, possible optical counterpart
- GRB030501 localized by INTEGRAL
- GRB030425: CrAO optical observation
- IPN triangulation of GRB030429 (annulus)
- IPN triangulation of GRB030428 (two large error boxes)
- GRB 030329 Oprical observations in Rozhen observatory
- GRB 030429: ROTSE-III observations
- GRB 030324: Radio Observations
- GRB030329 observed as a sudden ionospheric disturbance (SID)
- IPN triangulation of GRB030426 (annulus)
- SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
- IPN triangulation of GRB030425 (single error box)
- GRB030329, SPM optical observations (Correction)
- GRB030329, SPM optical observations
- GRB 030329, the review of the sky area in plate archive (1950-1998)
- GRB 030329: Spectral Evolution of SN 2003dh
- Optical Observations of GRB 030418 with Magellan
- GRB 030329: optical spectropolarimetry at VLT
- IPN triangulation of GRB030422C (annulus)
- IPN triangulation of GRB030422B (annulus)
- GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
- GRB030329: optical polarization
- IPN triangulation of GRB030422 (two large error boxes)
- GRB 030329 3.5 and 6 cm radio observations at RTF-32 telescope
- GRB030329, optical observation
- IPN triangulation of GRB030421 (annulus)
- MASTER:optical observations GRB030418
- MASTER:optical observations probable GRB030414
- GRB030329: 444 AAVSO Measurements
- IPN triangulation of GRB030419 (annulus)
- MASTER:optical observations GRB030416
- ROTSE-III prompt optical detections of GRB 030418
- GRB030418: Upper limits from recent and historical observations.
- GRB030418: Kiso near infrared observations
- GRB 030418: Optical afterglow
- GRB 030418: Finder for afterglow candidate
- GRB 030418: Optical afterglow candidate
- GRB 030329 OT position
- GRB030329: Optical Observations
- OT GRB 030329: early UBVRcIc spectral evolution
- GRB030329, UBVRI polarimetry, R-polarization
- GRB 030329: SARA Optical Observations
- OT GRB 030329: early spectrum
- GRB030329: VR Photometry at TNG
- GRB030324: Candidate Optical Afterglow (Erratum)
- GRB030324: Candidate Optical Afterglow
- IPN triangulation of GRB030414 (small error box)
- GRB 030413: Optical Observations
- GRB 030329 Rc observations
- IPN triangulation of GRB030413 (small error box)