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').
19129 results found.
- LIGO Virgo G194575: MWA Observations
- LIGO/Virgo G194575: RATIR Observations of Nearby Galaxies in the 1sigma Error Region
- LIGO/Virgo G194575: more details on transients from Pan-STARRS in the RA=1hr localisation region
- LIGO/Virgo G194575: Fermi GBM Observations
- LIGO/Virgo G194575: Mini-MegaTORTORA observations
- LIGO/Virgo G194575: transients from Pan-STARRS in the RA=1hr localisation region
- LIGO Virgo G194575: TZAC TAROT observations
- GRB 151022A: MITSuME Okayama Ks-band upper-limit
- GRB 151022A: MASTER-Ural observations
- GRB 151021A: MITSuME Okayama Ks-band upper-limit
- GRB 151021A: Swift/UVOT Detection
- LIGO/Virgo G184098: LOFAR follow-up
- GRB 151004A: Swift-XRT follow-up observations
- Trigger 659734: Swift detection of SAX J1750.8-2900 or other source near Galactic center
- LIGO/Virgo G184098: VLA follow-up of iPTF15cyk
- LIGO/VIRGO G184098 : PESSTO classifications of PanSTARRS transients in the northern region
- GRB 151006A: OSN optical upper limit
- GRB 151006A: MITSuME Okayama Ks-band upper-limit
- GRB 151006A: Swift/UVOT Upper Limits
- LIGO/Virgo G184098: Further VST-ESO PARANAL observations
- Trigger 657564 / GRB 151004A: Swift BAT and XRT refined analysis
- LIGO/VIRGO G184098 : PESSTO classification of PS15cbm in the northern region
- LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
- Trigger 657564 / GRB 151004A: Swift/UVOT Upper Limits
- Swift Trigger 657564: MASTER-NET early optical observations.
- LIGO/Virgo G184098: MASTER OTs detection and Scenario Machine prediction
- GRB 151001A: RATIR Observations
- GRB 151001B: Swift/UVOT Upper Limits
- GRB 151001A: Swift/UVOT Detection
- GRB 151001B: MASTER-NET early optical observations.
- LIGO/Virgo G184098: spectral classification of PS15cci
- GRB 150925A: Swift/UVOT Upper Limits
- LIGO/Virgo G184098: LOFAR follow-up
- LIGO/Virgo G184098: ASKAP followup
- LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
- LIGO/Virgo G184098: optical transient search with Kiso Schmidt telescope and KWFC on behalf of J-GEM collaboration
- LIGO/VIRGO G184098 : classifications of transients from the LSQ observations
- LIGO/Virgo G184098: transient search with VISTA
- ANTARES neutrino detection: Fermi GBM Observations
- LIGO/Virgo G184098: DESGW followup program
- LIGO/Virgo G184098: SkyMapper observations
- LIGO/Virgo G184098: TAROT network optical observations
- LIGO/Virgo G184098: La Silla - QUEST Followup
- LIGO/Virgo G184098: Swift follow-up observations
- LIGO/Virgo G184098: MWA Followup
- LIGO/Virgo G184098: DESGW followup program
- LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
- LIGO/Virgo G184098: Nearby Galaxies in Error Circle
- LIGO/Virgo G184098: Fermi-GBM ground-based follow-up
- LIGO/Virgo G184098: Observations from the TOROS collaboration
- LIGO/Virgo G184098: iPTF Optical Transient Candidates
- LIGO/Virgo G184098: VST-ESO PARANAL observations
- LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
- Instructions for reporting follow-up observations related to LIGO/Virgo G184098
- LIGO/Virgo G184098: observations by MASTER
- LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
- LIGO/Virgo G184098: Swift follow-up observations
- GRB 150910A: AAO optical observations
- GRB150915A : IRSF NIR upper limits
- GRB 150915A: NOT observations of a brightening afterglow
- GRB 150915A: Swift UVOT upper limits
- GRB 150906B: Further analysis of the Konus-Wind data
- GRB 150910A: Mt. Terskol observatory optical observations
- GRB 150910A: TSHAO optical observations
- GRB 150915A: VLT/X-shooter redshift
- GRB 150915A: GROND detection of an optical counterpart candidate
- GRB 150915A: MASTER-NET optical observations
- GRB 150910A: T100 observations
- GRB 150911A: GROND Upper Limits
- GRB 150910A: Continued RATIR Observations
- GRB 150907A: Swift-XRT afterglow detection
- GRB 150912A: Swift-XRT and UVOT observations
- GRB 150910A: RATIR Observations
- GRB 150912A: MASTER-IAC optical observations
- GRB 150912A: Swift ToO observations
- GRB 150906B: theoretical estimation of redshift and isotropic energy
- GRB150910A: P60 Observations
- GRB150911A: P60 Observations
- GRB 150911A: Swift/UVOT Upper Limits
- GRB 150910A: AAO optical observations
- GRB 150910A: Chuguev observatory optical observations
- GRB 150910A: VLA Detection
- GRB 150910A: continued SAO RAS optical observations
- GRB150911A MITSuME Okayama Ks-band upper-limit
- GRB 150910A: TSHAO optical observations
- GRB 150910A: NOT observations of the afterglow
- GRB 150910A: MITSuME Okayama Ks-band Observation
- GRB 150910A: GROND observation of the afterglow
- GRB 150910A: SAO RAS optical photometry
- GRB 150910A: Swift/UVOT Detection of a Brightening Afterglow
- GRB 150910A: Nanshan optical observations
- GRB 150910A: LCOGT FTN afterglow observations
- GRB 150910A: KAIT Optical Afterglow Detection
- Short GRB 150906B: proximity to NGC 3313 galaxy group
- GRB150907A: Swift/UVOT observations
- GRB 150907B: MASTER-SAAO early optical observations
- GRB 150907B: GROND Upper Limits
- GRB 150907B: Swift-XRT observations
- GRB 150907A: Swift-XRT observations
- GRB 150907A: Tiled Swift observations