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.
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"12318 results found.
- GRB030329: RTT150 optical observations and upper limit for a host
- GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
- GRB030329: RTT150 optical observations and upper limit for a host
- GRB030329 observed as a sudden ionospheric disturbance (SID)
- GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
- GRB030418: Upper limits from recent and historical observations.
- GRB030329: HET spectroscopic monitoring
- GRB030328: R upper limit after 6 hours by MASTER
- GRB 030329: Light curve observed during the change of its slope.
- GRB 030329: Optical pre-Imaging
- GRB 030329: Upper limit from 5.6 hours before trigger
- GRB030329: Upper limits from recent and historical observations.
- RXTE detection of GRB 030329 afterglow
- GRB 030328: OT photometry
- GRB030323: Upper limits from recent and historical observations.
- IPN upper limit to a GRB associated with SN2003L
- GRB 030227: Optical limit at RIKEN
- GRB030226: Analysis of Chandra data
- GRB030227: Kiso optical upper limit
- GRB 030226: R band polarimetric observations
- GRB 20030226: Upper limits from recent and historical observations
- GRB 030226 simultaneous optical observations
- GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
- GRB030115 submm upper limit
- GRB 030115, simultaneous observations by BOOTES-1
- GRB 021211: R-band observations at late-time
- GRB021211, radio observations
- GRB021211: APO optical observations
- SUB-MM SEARCH FOR GRB 021211
- GRB 021211 Milagro GeV/TeV Observations
- GRB021211 - Upper limits from recent and historical observations
- GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
- GRB 021201: BOOTES simultaneous optical observations
- GRB 021004 submm observations
- GRB 021004 submm observations
- GRB 021004 - Unusual Radio-to-Submm Spectrum
- GRB021004: not fading anymore?
- GRB 021004: polarimetric observations
- IRAM Millimeter detection of GRB 021004
- GRB 021004: Optical observations at RIKEN
- GRB021004: Upper limits from recent and historical observations
- GRB 020813 multiband optical observations
- GRB 020625, optical observations
- AXP 1E2259+586: quasi-simultaneous optical observation
- GRB 020531, INT+WFC deep optical upper limits
- GRB 020531, simultaneous optical observations
- GRB 020418, optical/near-IR observations
- GRB020531: Upper Limit for Detection of Two TAROT Sources
- GRB020331: Optical Observations of Afterglow Candidate
- GRB011212: Optical Observations
- SN 2002ap - peak brightness date (SN/GRB?)
- GRB 020322: Optical Observations
- GRB 020305: Optical observations
- Type Ic SN2002bl (SN/GRB?) Radio Observations
- GRB020127: Further VLA Observations of Possible Counterparts
- IPN Upper Limits to a GRB Associated With SN2002ap
- GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
- GRB011212, Optical Observations
- Optical polarization observations for GRB011211
- GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
- GRB 011121: J-band observations
- GRB010921 - Milagro GeV/TeV Observations
- GRB 011121: HST Scheduled
- GRB 011030 R band observations
- GRB 011030 I-band Observation
- Optical observation of SGR 1806-20 at the 6-m SAO telescope
- GRB010921, optical observations
- GRB000418: HST/STIS Second-epoch Observations
- GRB010214, optical observations
- SGR 1900+14, Chandra observations
- GRB 010222 - HEGRA GeV/TeV Observations
- GRB010220 optical obsercations
- Sub-millimeter Excess/GRB 010222
- GRB 010222
- GRB010220, Radio and Optical Observations
- GRB 010214: X-Ray afterglow
- Optical Observations of GRB 001018 at Keck
- GRB001120, optical observations
- GRB 001109: deep JHK upper limits
- GRB000630, Optical Observations
- GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
- GRB000210, Radio Observations
- GRB 991208, radio observations
- GRB991216 radio observations
- GRB991106: BeppoSAX/BATSE results
- GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
- GRB991014 BATSE Observations
- Infrared and Optical Observations of GRB990705
- GRB 990506, optical observations
- ASM/IPN error box for GRB 990308 (BATSE #7457)
- GRB990123, Optical observation
- GRB 990123: Continued Radio Observations
- GRB 990123: near-infrared observations.
- GRB990123: NIR Observation
- GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
- GRB 990123, new radio source
- GRB 981226: radio variable
- GRB981220, Correction to GCN 179
- GRB981220, Optical Observations
- GRB 981220 Optical observations