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"11504 results found.
- IPN triangulation of GRB030629 (annulus)
- GRB030329: second XMM-Newton observation
- GRB030418: R optical observations
- HETE detection of burst from SGR1806-20
- GRB030329 -- RATAN-600 data in April-May
- GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
- IPN triangulation of GRB030606 (two alternate error boxes)
- GRB 030528: tentative NIR counterpart
- GRB030528(=H2724): Observations with the Chandra X-ray Observatory
- IPN triangulation of GRB030601 (annulus)
- GRB030329, SPM optical observations
- GRB 030329: optical observations
- GRB 030329/SN 2003dh: Jitter Episode
- GRB 030329: optical photometry at various french observatories
- GRB030329, Optical observations
- GRB 030329/SN 2003dh: Possible increase in brightness
- GRB030329: XMM-Newton observation
- GRB030429, refiend optical brightness
- GRB 030329: Optical limit (contemporaneous photography)
- GRB030501C triangulation (annulus)
- GRB 030329 Optical Observations
- GRB 030329, BVRI photometry
- GRB030429: Optical Observations
- GRB 030501: TAROT possible candidate counterpart
- GRB030429, possible optical counterpart
- GRB 030429: ROTSE-III observations
- SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
- GRB 030329, the review of the sky area in plate archive (1950-1998)
- GRB030329, optical observation
- MASTER:optical observations GRB030418
- MASTER:optical observations probable GRB030414
- ROTSE-III prompt optical detections of GRB 030418
- GRB030329: VR Photometry at TNG
- IPN triangulation of GRB030413 (small error box)
- IPN triangulation of GRB030406 (small error box)
- GRB030329: BV photographic observations
- GRB030329: RTT150 optical observations
- GRB030329: Kiso B and R band observations
- GRB 030329: BV photographic observations
- GRB 030329, BVRI photometry
- GRB030329: final R-band light curve by MASTER
- GRB030329 - more 15 GHz radio data
- OT GRB light curves and SN predictions
- GRB 030329, BRI photometry
- GRB030328: Full Observation, X-ray Fading and Spectrum Measured
- Further AAVSO V,B,R observations of GRB030329
- GRB 030329: Additional Mt. Laguna Optical Observations
- GRB030329: further optical photometry and evidence for a light curve discontinuity
- GRB030329 - OT rebrightens
- AAVSO V & R observations of GRB030329
- GRB 030329: optical observations
- GRB030329 - Light curve flattening
- GRB030328: X-ray Fading and Spectrum Measured with Chandra
- GRB 030329: visual observations
- GRB030328: X-ray Afterglow Observed with Chandra
- GRB 030329, R-band observations, supplement
- GRB030329:optical observations by MASTER
- GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
- RXTE detection of GRB 030329 afterglow
- GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
- GRB 030328: Finding chart
- GRB 030328: Optical afterglow candidate
- GRB030324, optical observations
- GRB030324, Optical Observations
- GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
- GRB 030324, optical observations
- IPN triangulation of GRB030317 (annulus)
- GRB 030227: Optical limit at RIKEN
- IPN triangulation of GRB030306 (single small error box)
- IPN triangulation of GRB030306 (two small error boxes)
- IPN triangulation of GRB030306 (intense; annulus only so far)
- GRB030226: Analysis of Chandra data
- GRB 030227: fading of candidate optical afterglow 'S1-A'
- GRB 030227, possible optical counterpart of XMM-Newton source
- GRB030227 - faint tentative OT candidate
- GRB 030227: Kyoto optical observation
- GRB030227 localized by INTEGRAL
- GRB 030226, optical observations
- GRB 030226 Optical Spectra and R,I,z' Imaging
- GRB030226: Candidate optical afterglow
- GRB 030217: Optical Observations at 4, 5, and 6 Days
- GRB030217: optical observations
- GRB030131: Kiso optical limit for corrected position
- GRB030131: Optical limits for corrected position
- GRB 030131: afterglow candidate
- GRB030131: Optical limit
- GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
- GRB 030115, simultaneous observations by BOOTES-1
- GRB030115: R-band counterpart of IR candidate
- GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
- GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
- GRB 030115, no optical candidate
- IPN triangulation of GRB030102B (portion of annulus)
- GRB on 20030101 seen by SPI-ACS
- GRB021219: a long GRB localized by INTEGRAL
- IPN detection of continued activity from SGR1806-20
- GRB 021201: Optical Observations
- GRB 021211: early break in light curve
- GRB021211: Optical observations in CrAO
- Chandra observation of the IPN error box of GRB021201 (short/hard)