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').
578 results found.
- SGR 1E 1841-045: early optical limit by "Pi of the Sky"
- SGR 1E 1841-045: Swift-BAT refined analysis
- SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
- SGR 1E 1841-045: Swift-BAT refined analysis
- SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
- GRB 110406A: Positional coincidence with NGC 404
- ICSP VLF observation of multiple SGR-like bursts from 1E 1841-045 on Feb. 9, 2011
- Fermi GBM detection of an SGR-like burst
- SGR-like outburst from the magnetar 1E 1841-04.5
- Fermi GBM detection of a burst from a galactic source
- Swift-BAT trigger 421695 is likely not astrophysical
- Swift-BAT refined analysis of trigger 421262
- An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
- Spin down rate and inferred dipole magnetic field of the new soft gamma-ray repeater SGR 1833-0832
- Fermi/GBM and Swift/BAT detection of a burst from SGR 1806-20
- SGR 1833-0832: Swift/UVOT Upper Limits
- SGR 1833-0832: Archival Chandra Observations
- SGR 1833-0832 is pulsed at 7.56 seconds
- SGR 1833-0832 is pulsed at 7.56 seconds
- Possible pulsation period in SGR 1833-0832
- Discovery of the Spin Period of SGR 1833-0832
- Probable SGR 1833-0832: Swift-XRT refined analysis
- Probable SGR 1833-0832: Enhanced Swift-XRT position
- Swift-XRT refined position of the probable new SGR 1833-0832
- Swift-BAT refined analysis of the probable new SGR 1833-0832
- GRB 100319A: Swift detection of a burst; possible SGR
- Swift Trigger #382159 is due to XTE J1752-223
- SGR 0418+5729 Fermi/GBM Detection of Pulsations
- RXTE Discovery of Pulsations from SGR 0418+5729
- Konus-RF observation of SGR burst 090605A
- Discovery of a new soft gamma repeater source, SGR 0418+5729
- Refined analysis of ICSP VLF observation of SGR J1550-5418 bursts on 22nd January, 2009
- GRB 090417A: Early-type nature of the putative host
- GRB 090417A: nearby galaxy redshift
- SGR J1550-5418: two Fermi GBM triggers on March 22
- A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
- ATCA observation of SGR J1550-5418
- GRB 090303: Fermi GBM detection
- Konus-RF catches first GRB and SGR bursts
- SGR J1550-5418
- Ongoing activity of AXP/SGR 1E1547.0-5408
- SGR activity seen by BAT during ICSP Ionospheric Events
- Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
- Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
- ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
- Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
- Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
- AXP 1E1547.0-5408: RHESSI observations up to 400 keV
- Konus-Wind detection of very bright SGR-like burst on January 25, 2009
- Trigger 340734: Swift detection of a possible short burst
- AXP 1E1547.0-5408 activity with SGR bursts
- Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
- SGR 1806-20: Fermi GBM detection.
- SGR 1806-20: Fermi GBM detection
- SGR 0501+4516: optical observations in August
- GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
- SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
- SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
- Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
- GRB 081024: Swift detection of a burst
- AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
- SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
- Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
- Trigger 330353: Swift detection of a Galactic short soft burst
- SGR 0501+4516: preliminary results of the Suzaku ToO observation
- SGR 0501+4516 : P200 i-band observations
- SGR J0501+4516: radio pulsar searches with GBT and WSRT
- 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