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"
232 results found.
- LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limit for EP240426a
- LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limits for Swift/XRT candidates
- EP240408a: GROND detection of a candidate counterpart
- X-ray transient EP240315a: GROND J-band detection
- GRB200120A: SRG/eROSITA discovery of X-ray afterglow
- GRB131018A, optical observations
- GRB 130420B: Fermi GBM observation
- GRB 130420A: Fermi GBM observation
- GRB 120919A: Fermi GBM detection
- GRB120816A: OPTIMA discovery of optical counterpart
- GRB 120729A: Fermi GBM observation
- VLT/FORS2 redshift of GRB120716A
- GBM triggers 120705.153 & 120705.322 were not GRBs
- GBM triggers 120604.526 & 120604.399 were not GRBs
- Fermi Gamma-ray Burst Monitor trigger 120527.573 is not a GRB
- GRB120404A: GROND observations show steeply decaying afterglow
- GRB 120212A: Fermi GBM observation
- GRB 111222A: Fermi GBM observations
- GRB 110918A: GROND detection of the afterglow candidate
- A new photometric resource for GRB observers
- Fermi Gamma-ray Burst Monitor trigger 110809.346 is not a GRB
- GRB 110412A: Fermi GBM observation
- GRB 110406A: An exceptionally bright burst detected by INTEGRAL SPI-ACS
- Fermi GBM trigger 319534757 (110216319) is not a GRB
- GRB 100528A: Fermi GBM observation
- Fermi/GBM trigger 295791986 - unreliable location
- INTEGRAL trigger 5994 / GRB 100331A: GROND detection of a variable source
- GROND observations of GRB100316D/SN2010bh
- GRB 100305A Optical Observations
- GRB091109A: VLT/FORS2 spectroscopic redshift
- GRB 091127 : GROND observations
- GRB 091102A: Fermi GBM observation
- GRB 091026: GROND Upper Limits
- GRB091024: VRcIc Afterglow Observations
- GRB 090929A: Suzaku WAM observation of the prompt emission
- GRB 091003A: Fermi GBM detection
- GRB 090929A: Fermi GBM detection
- GRB090922A: correction to Fermi location
- GRB 090922A: Fermi GBM detection
- GRB 090831A: Suzaku WAM observation of the prompt emission
- GRB 090831: Fermi GBM detection
- GRB 090820B: Fermi GBM detection
- GRB 090812: GROND Observations of the Optical/NIR Afterglow
- GRB 090621A: MAGIC telescope GeV observation
- GRB 090717B: Fermi GBM detection
- GRB 090720: Fermi GBM detection
- GRB 090706: Fermi GBM detection
- GRB 090630: Fermi GBM detection
- GRB 090625B: Fermi GBM observation
- GRB 090625: Fermi GBM detection
- GRB 090623: Fermi GBM detection
- GRB 090621D: Fermi GBM detection
- GRB 090621C: Fermi GBM detection
- GRB 090621: Fermi GBM observation
- GRB 090620: Fermi GBM detecion
- GRB 090529C: Fermi GBM detection
- GRB 090529B: Fermi GBM detection
- GRB090510: VLT/FORS2 spectroscopic redshift
- Fermi Gamma-ray Burst Monitor trigger 263649437 is not a GRB
- GRB 090510B: Fermi GBM detection
- GRB 090418A BVRcIc field calibration
- GRB 090423 limiting magnitudes
- GRB090418A Rc-band photometry
- GRB 090328: Fermi-LAT refined analysis
- GRB 090328: Fermi GBM Spectral Analysis
- GRB 090320A: Fermi GBM detection
- GRB090310: Fermi GBM detection
- GRB 090306C: Fermi GBM detection
- GRB 090303: Fermi GBM detection
- GRB 090304: Fermi GBM detection
- GRB 090213: Fermi GBM detection
- GRB 090107B optical observations
- GRB080310, BVRcIc field calibration
- GRB080319B, BVRcIc field calibration
- GRB071010B, BVRcIc field calibration
- GRB060418, BVRcIc field calibration
- GRB060124, BVRcIc field calibration
- Recent GRB UBVRcIc field photometry
- GRB050915, optical observations
- GRB050824, I-band imaging
- GRB050525, GRB050607, GRB050802 BVRcIc field photometry
- GRB050820a BVRcIc field photometry
- GRB 050801, afterglow observations
- GRB050730, afterglow observations
- GRB050709, optical observations
- Recent GRB BVRcIc field photometry
- XRF050522, BVRcIc field photometry
- GRB050505: AAVSO observations
- GRB041219, early time observations
- GRB041219, BVRcIc field calibration
- GRB041218, BVRcIc field calibration
- Optical transient (GRB?) in Lynx
- GRB041211, BVRcIc field calibration
- GRB040924, BVRcIc field calibration
- GRB041006, BVRcIc field calibration
- GRB 040916: Afterglow Color at Early Times
- XRF040916, optical observations
- XRF040916, Ic observations
- XRF040912, BVRcIc field calibration
- XRF040916, BVRcIc field calibration