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').
9654 results found.
- GRB030723: Upper limits from historical observations
- GRB030725, possible optical transient
- XRF030723, BVRcIc field photometry correction
- XRF030723, ROTSE-III Early Observations
- Konus-Wind detection of the bursts from SGR1806-20 region
- SGR 1806-20, submm observations
- H2768, H2770, and H2771: Three Bursts from SGR1806-20
- IPN triangulation of GRB030717 (annulus)
- RXTE PCA Observations of SGR1806-20 Region
- Triangulation of GRB030715 (single large error box)
- IPN triangulation of GRB030714 (two large error boxes)
- IPN triangulation of GRB030715 (two large error boxes)
- IPN detection of renewed activity from SGR1806-20
- 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
- GRB030329 observed as a sudden ionospheric disturbance (SID)
- 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