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"4252 results found.
- GRB 080928: GROND DETECTION
- GRB 080925: Fermi GBM Detection
- SGR 0501+4516: preliminary results of the Suzaku ToO observation
- GRB 080915B, Swift-BAT refined analysis
- SGR 0501+4516 : P200 i-band observations
- GRB 080905C: Fermi GBM detection
- SGR J0501+4516: radio pulsar searches with GBT and WSRT
- Swift Trigger 324122 is again known source Swift J1842.5-1124
- GRB 080906: Swift detection of a burst with optical afterglow
- Recent VLA non-detection of SGR 0501+4516
- SGR 0501+4516: Spin Down Rate and Inferred Dipole Magnetic Field
- SGR 0501+4516: preliminary results of the first XMM-Newton observation
- nIR observations of SGR 0501+4516
- INTEGRAL ToO observation of SGR0501+4516
- SGR 0501+4516: Confirmation of the NIR counterpart
- SGR 0501+4516: Detection of possible optical counterpart
- SGR 0501+4516: WHT observations of the possible near-infrared counterpart
- VLA non-detection of SGR 0501+4516
- Radio Detection of SGR 0501+4516: Retraction
- SGR 0501+4516: XMM-Newton monitoring schedule
- SGR 0501+4516: Decline in Activity
- SGR 0501+4516: Proximity to supernova remnant HB9
- Enhanced Swift-XRT position of SGR 0501+4516
- SGR 0501+4516: GMRT Radio Observation at 618 MHz
- SGR 0501+4516: Swift XRT measure of the spin period
- SGR 0501+4516: Fermi GBM (formerly GLAST Burst Monitor) observations of three exceptionally intense outbursts
- Soft Gamma Repeater SGR 0501+4516: GBM Detection of multiple bursts
- Suzaku ToO Observation of SGR 0501+4516
- SGR 0501+4516: radio pulsar searches with GBT and WSRT
- Konus-Wind observations of new SGR 0501+4516
- INTEGRAL ToO Observation of SGR0501+4516
- Radio Detection of SGR 0501+4516
- SGR 0501+4516: MDM Optical Observations
- SGR 0501+4516: Astrotel-Caucasus optical observations
- SGR 0501+4516: UKIRT detection of possible infra-red counterpart
- SGR 0501+4516: WSRT Radio Observations
- Trigger 321551: Continued Large Flaring of SGR 0501+4516
- SGR 0501+4516: optical observations
- Swift Trigger 321481: A Large Flare from SGR 0501+4516
- SGR 0501+4516: Swift-BAT refined analysis of the 3 discovery events
- Discovery of the Spin Period of the New Soft Gamma Repeater SGR 0501+4516
- Third event from SGR 0501+4516
- GRB 080822 (SGR 0501+4516): archival optical observations
- New Soft Gamma Repeater 0501+4516 was GRB 080822
- GRB 080727B: Late VLT imaging
- Trigger 317393: Swift detection of a possible GRB
- Trigger 317205: Swift detection of an outburst from XTE J1701-407
- GRB 080710, Swift-BAT refined analysis
- GRB 080710: Swift detection of a burst
- GRB 080707: Swift detection of a burst
- GRB 080702B : Burst detected in BAT during Swift slew
- GRB 080701: Swift detection of a burst
- GRB 080613B: Swift detection of a burst
- GRB 080604: Swift detection of a burst with an optical afterglow
- SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
- Konus-Wind observation of reactivation of SGR 1627-41
- Reactivation of SGR 1627-41
- GRB 080515: KPNO 4m NIR afterglow detection
- GRB 080506: NAYUTA Optical Observation
- GRB080430: Optical observation in AsU CAS Ondrejov & Brno
- GRB 080426: Swift detection of a possibly short burst
- GRB 080413A: MOA-II optical afterglow observations
- GRB 080330, SMARTS optical/IR afterglow observations
- GRB 080319A: UVOT Observations
- GRB 080319C: Swift-XRT Team Refined Analysis
- GRB 080319C: Swift detection of a burst with an optical afterglow
- GRB080310: Super-LOTIS suggestion of brightening
- GRB080307, optical upper limit
- GRB 080307: retraction of UVOT candidate
- GRB 080303A: ROTSE-III Optical Limits
- GRB080229: Possible optical afterglow
- UVOT analysis for GRB080229
- GRB 080218: Swift detection of a burst
- GRB 080207, Swift-BAT refined analysis
- GRB 080207, Swift-BAT refined analysis
- GRB 080129: Swift-XRT refined analysis
- GRB 080129: Gemini-South Imaging Observations
- Konus-Wind observation of GRB 080122
- GRB 080121: Swift-BAT detection of a very weak, short burst
- IPN triangulation of very bright GRB 071125
- Disregard the "GRB 071126" position
- GRB 071118: Swift detection of a burst
- GRB 071101: Swift detection of a burst
- GRB 071028: Swift-XRT Team refined analysis
- GRB 071028: Swift detection of a burst
- GRB071020, optical upper limit
- GRB 071017: a SHORT GRB detected by INTEGRAL
- GRB071010B: Swift/XRT detection
- GRB 070911, SMARTS optical/IR afterglow observations
- GRB 070920B: ROTSE-III Early Optical Limits
- INTEGRAL ToO observations of SGR1806-20
- GRB 070920b, SMARTS optical observation
- SGR1806-20: Swift-BAT detection of enhanced activity
- GRB 070911: Swift XRT refined analysis
- GRB 070911, Swift-BAT refined analysis
- Intense burst from SGR 1806-20 detected on September 7
- GRB 070810: ROTSE-III Detection of Optical Counterpart
- GRB 070809: ROTSE-III Optical Limits
- GRB 070808: Xinglong TNT optical Upper Limit
- GRB070808: Optical observations with KANATA