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"26507 results found.
- GRB 030429: redshift from VLT spectroscopy
- GRB030501B triangulation (single error box)
- GRB030429: Optical Observations
- GRB030501: TAROT candidate afterglow present in archival images
- IPN triangulation of GRB030501 (IBIS event; annulus)
- GRB 030429: confirmation of afterglow candidate
- GRB030429, possible optical counterpart
- GRB030425: CrAO optical observation
- GRB 030329 Oprical observations in Rozhen observatory
- IPN triangulation of GRB030425 (single error box)
- GRB 030329, the review of the sky area in plate archive (1950-1998)
- GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
- GRB030329: optical polarization
- IPN triangulation of GRB030422 (two large error boxes)
- MASTER:optical observations GRB030418
- MASTER:optical observations probable GRB030414
- GRB030418: Kiso near infrared observations
- OT GRB 030329: early spectrum
- GRB030324: Candidate Optical Afterglow
- IPN triangulation of GRB030414 (small error box)
- IPN triangulation of GRB030413 (small error box)
- Superluminal motion in GRB 030329 (Correction)
- Superluminal motion in GRB 030329
- GRB030329, optical position
- IPN triangulation of GRB030406 (small error box)
- IPN triangulation of GRB050403 (small error box)
- GRB030329: HET spectroscopic monitoring
- Kiso observation of the GRB030329 at April 6
- GRB 030329, color evolution
- GRB030328, UBVRcIc field photometry
- GRB 030329 Optical observations
- GRB030329: Kiso B and R band observations
- GRB030329: More AAVSO VR obs
- GRB 030329: BV photographic observations
- SDSS 0.5m PT observations of GRB030329 (correction)
- SDSS 0.5m PT observations of GRB030329
- GRB 030329, nearby galaxies
- GRB030329: final R-band light curve by MASTER
- GRB030329, optical observation
- GRB030329, new UBVRcIc field photometry
- GRB 030329, light curve and SN prediction
- GRB030328: Full Observation, X-ray Fading and Spectrum Measured
- GRB030329: Optical observations at Teramo
- GRB 030329: Radio observations at GMRT
- GRB 030329: Additional Mt. Laguna Optical Observations
- GRB 030329: Observations with ANDICAM
- GRB 030329: fitting parameters and re-brightening
- triangulation of GRB 030331 (single error box)
- GRB 030329: optical observations
- GRB 030329, optical spectroscopy
- GRB 030329: fading X-ray afterglow with RXTE
- GRB 030329: OT observations at Kanazawa
- GRB 030324: Optical and NIR Observations
- GRB030329: R band light curve by MASTER
- GRB030329 - Light curve flattening
- GRB 030324, optical search
- GRB 030329, optical observations
- GRB030328: X-ray Fading and Spectrum Measured with Chandra
- GRB030329a: detection by Konus-Wind
- GRB030329b: detection by Konus-Wind and Helicon-CoronasF
- GRB 030329: Light curve observed during the change of its slope.
- GRB030329, BVRcIc field photometry
- GRB030329, SPM optical observations
- GRB030329 optical observations
- GRB 030329: Optical pre-Imaging
- GRB 030329: Upper limit from 5.6 hours before trigger
- GRB030328: X-ray Afterglow Observed with Chandra
- GRB 030329, R-band observations
- GRB030329: Upper limits from recent and historical observations.
- GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
- RXTE detection of GRB 030329 afterglow
- GRB 030329: Optical Afterglow Observations
- GRB 030329: precise position from Kyoto images
- GRB 030328: optical observations
- GRB 030329: Optical afterglow fading
- GRB 030328: OT photometry
- GRB030328: optical spectroscopy at TNG
- GRB030328: optical photometry at the TNG
- GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
- GRB 030328: Optical observations
- GRB 030328: Optical afterglow candidate
- GRB030324 optical observation
- GRB030131, BVRcIc field photometry
- Possible GRB030323 localized by INTEGRAL
- GRB030323: Detection on 2003/03/24
- IPN triangulation of GRB030326 (single small error box)
- IPN triangulation of GRB030325 (two small error boxes)
- GRB030323: V, R, I photometry
- GRB 030324 (HETE #2641): Optical observations
- GRB030324, Optical Observations
- GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
- GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
- VLT/FORS2 spectra of GRB 030323
- GRB030323, optical observations
- GRB030324, BVRcIc field photometry
- GRB030323, BVRcIc field calibration
- GRB 030324, optical observations
- IPN triangulation of GRB030320 (small error box)
- Possible GRB 030320 localized by INTEGRAL
- IPN upper limit to a GRB associated with SN2003L