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"36789 results found.
- IPN triangulation of GRB030731 (annulus)
- IBAS GRB Alerts 1011-1017 NOT CONFIRMED
- IPN triangulation of GRB030725 (=H2779; small error box)
- XRF030723 (=H2777): Second Epoch Magellan Observations
- GRB 030725: optical observations.
- GRB030725, optical transient observations
- IPN triangulation of GRB030726 (large error box)
- IPN triangulation of GRB030722 (large error box)
- IPN triangulation of GRB030721 (large error box)
- XRF030723 Radio Observations
- XRF030723(=H2777): Chandra Observations
- Magellan Observations of XRF030723 (=H2777)
- GRB030723: Upper limits from historical observations
- GRB030725, possible optical transient
- XRF030723: Palomar observations and proposed counterpart
- GRB030725 (=H2779): A Bright GRB Localized by HETE
- XRF030723: optical observations
- XRF030723 (= H2777): Chandra Observations Scheduled
- XRF030723, BVRcIc field photometry
- XRF030723, optical observations
- GRB030723, optical observations
- IBAS GRB Alerts 969 970
- IPN triangulation of GRB030717 (annulus)
- GRB030329: Subaru Optical Spectroscopy
- Triangulation of GRB030715 (single large error box)
- 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
- IPN triangulation of GRB030626 (single large error box)
- IPN triangulation of GRB030626 (two large error boxes)
- GRB030418: R optical observations
- 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)
- 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)
- GRB030528: Chandra TOO Planned
- GRB 030519B: optical observations.
- 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)
- GRB 030329/SN 2003dh: Possible increase in brightness
- GRB 030329: HST ACS Observations of the Host
- GRB 030329 Optical Observations
- GRB 021004: HST observations
- GRB030324: Further Observations of the Candidate Optical Afterglow
- 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)
- 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
- GRB 030329: Optical limit (contemporaneous photography)
- GRB030418, BVRcIc field photometry
- GRB 030429: Redshift of neighbor galaxy