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').
- Triangulation of GRB030714 (single large error box)
- 030716 NOT a GRB
- IPN triangulation of GRB030714 (two large error boxes)
- IPN triangulation of GRB030715 (two large error boxes)
- GRB030329: RTT150 optical observations
- GRBlog: Compilation of all GCN Circ. data
- IPN detection of renewed activity from SGR1806-20
- IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
- IPN triangulation of GRB030710 (annulus)
- IPN triangulation of GRB030709 (annulus)
- GRB030706 triangulation (single large error box)
- IPN triangulation of GRB030706 (annulus)
- IPN triangulation of GRB030629 (annulus)
- GRB030629 triangulation (Konus-Wind -- Helicon annulus)
- 030629 NOT a real GRB
- GRB030329, optical observation in May
- IPN triangulation of GRB030626 (single large error box)
- IPN triangulation of GRB030626 (two large error boxes)
- GRB030329: second XMM-Newton observation
- GRB030418: R optical observations
- HETE detection of burst from SGR1806-20
- GRB030329 -- RATAN-600 data in April-May
- Final IPN error ellipse for GRB021206 (the polarized GRB)
- GRB 021206, Radio afterglow candidate
- GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
- IPN triangulation of GRB030607 (annulus)
- IPN triangulation of GRB030606 (two alternate error boxes)
- GRB030329, SPM optical observations (Correction of GCN2075 R band)
- GRB 030528: Infrared Observations and the Proposed IR Counterpart
- IPN triangulation of GRB030605B (annulus)
- GRB 030528: Optical Observations
- IPN triangulation of GRB030605 (annulus)
- GRB 030528: tentative NIR counterpart
- GRB 030528, radio observations
- GRB030528(=H2724): Observations with the Chandra X-ray Observatory
- GRB030329, further radio observations at GMRT
- GRB030528, BVRI field photometry
- IPN triangulation of GRB030601 (annulus)
- GRB030329, SPM optical observations
- GRB030528: Chandra TOO Planned
- GRB 030519B: optical observations.
- MASTER: optical observation GRB030601
- GRB030528(=H2724): Revised SXC Localization
- GRB 030329: optical observations
- GRB 030329/SN 2003dh: Jitter Episode
- GRB 030528, Teramo optical observation
- GRB 030528 Bisei optical observation
- GRB030528 (H2724): A long GRB localized by HETE
- GRB 030329: Correction to GCN 2254
- GRB 030329: Optical Observations
- GRB 030528: Optical observations at RIKEN
- GRB 030528 (=H2724) Kyoto optical observation
- IPN triangulation of GRB030523B (annulus)
- GRB 030416: Optical Observations
- GRB 030329: Planned XMM-Newton Observation
- IPN triangulation of GRB030523 (annulus)
- GRB 030329: optical photometry at various french observatories
- GRB 030329: optical photometry at Belesta observatory (France)
- GRB030329, Optical observations
- GRB 030329/SN 2003dh: Possible increase in brightness
- GRB 030329: HST ACS Observations of the Host
- GRB 030329 Optical Observations
- GRB030329: XMM-Newton observation
- GRB 021004: HST observations
- GRB030324: Further Observations of the Candidate Optical Afterglow
- GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
- IPN triangulation of GRB030519B=H2716 (small error box)
- GRB 030418: Second Epoch Optical Observations with Magellan
- 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