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').
19136 results found.
- GRB 160117B: VLT/X-shooter spectroscopy
- GRB 160117B: iTelescope T17 optical observations
- GRB 160117B: NOT optical afterglow observations
- GRB 160117B: Swift/UVOT Detection
- GRB 160117B: LCOGT-SSO optical observations
- GRB 160117B: MASTER-Amur OT observations
- LIGO/Virgo G211117: Preliminary VLA observation summary of PS15dpn
- LIGO/Virgo G211117: Further Swift-XRT sources
- GRB 160113A: Swift-XRT observations
- GRB 160113A: Swift ToO observations
- GRB 160113A: iPTF P48 Observations and Optical Transient Candidates
- GRB 160104A: Swift/UVOT Detection
- LIGO/Virgo G211117: Swift observations of PS15dpn
- LIGO/Virgo G211117: iPTF Observations of PS15dpn
- LIGO/Virgo G211117: PESSTO classification of MASTER J165420.77-615258
- LIGO/Virgo G211117: VLA follow-up
- LIGO/Virgo G211117: Pi of the Sky observations
- LIGO/Virgo G211117: VISTA imaging
- LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
- LIGO/Virgo G211117: MASTER OT in ESO138-006 galaxy
- LIGO/Virgo G211117: Further Swift-XRT sources
- GRB 160104A: Nishi-Harima MINT Observations
- LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
- GRB 160104A: Spectroscopic observations from 10.4m GTC
- GRB 160104A: Mini-GWAC upper limit during prompt emission phase
- GRB 160104A: GWAC upper limit during prompt emission phase
- GRB 160104A: MITSuME Okayama Ks-band upper-limit
- LIGO/Virgo G211117: Fermi/LAT observations
- LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G211117: Gemini classification of 7 Pan-STARRS transients
- LIGO/Virgo G211117: LOFAR follow-up
- GRB 160102A: Swift-XRT observations
- LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G211117: PESSTO classification of Pan-STARRS transients
- LIGO/Virgo G211117: MASTER OTs 26.XII.2015 - 01.I.2016
- LIGO/Virgo G211117: CSS/CRTS observations on 29/30 Dec 2015 UT
- GRB 160102A: Tiled Swift observations
- LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28 - 30
- GRB 160101A: Swift/UVOT Detection
- GRB 160101A: Swift-XRT afterglow detection
- GRB 160101A: Tiled Swift observations
- LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G211117: FLOYDS Classification of SMTJ13331687-1607330 as a Two-Week-Old Type Ia Supernova
- LIGO/Virgo G211117: LBT follow-up imaging of iPTF15fhq
- LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
- LIGO/Virgo G211117: MAXI/GSC observations
- MASTER-NET observations of V404Cyg Swift Trigger 668877
- LIGO/Virgo G211117: Liverpool Telescope followup of EM candidates
- LIGO/Virgo G211117: VLA follow-up
- Trigger 668877: Swift detection of V 404 Cyg
- LIGO/Virgo G211117: MAGIC very-high energy gamma-ray observations
- LIGO/Virgo G211117: INAF TNG follow-up of MASTER OT J020906.21+013800.1
- LIGO/Virgo G211117: OAO-WFC NIR follow-up observations
- LIGO/Virgo G211117: SkyMapper observations and transient candidate
- V404Cyg Swift Trigger 668097: CrAO RT-22 radio observations
- LIGO/Virgo G211117: MASTER Observations of the 3 iPTF candidates
- V404Cyg Swift Trigger 668097: AbAO optical observations
- GRB 151228B: Swift/UVOT Detection
- LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
- LIGO/Virgo G211117: List of near-term future observation regions by Project Mini-GWAC of SVOM
- LIGO/Virgo G211117: iPTF Optical Transient Candidates
- LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28, 29
- GRB 151229A: Swift/UVOT observations
- LIGO/Virgo G211117: Further Swift-XRT sources
- GRB 151228A: T60 observations
- LIGO/Virgo G211117: DESGW program observations with DECam
- LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
- LIGO/Virgo G211117: Fermi GBM Observations
- LIGO/Virgo G211117: Optical follow-up with Kanata telescope
- LIGO/Virgo G211117: MASTER Observations and Inspection + OT
- LIGO/Virgo G211117: Pan-STARRS1 observations 2015-12-28
- LIGO/Virgo G211117: INAF VST-ESO PARANAL observations
- LIGO/Virgo G211117: Further Swift-XRT sources
- LIGO/Virgo G211117: Swift-XRT sources
- LIGO/Virgo G211117: SWASP optical observations
- LIGO/Virgo G211117: MASTER possible OT detection at the begining of inspection
- V404Cyg Swift Trigger 668097: TSHAO optical observations
- V404Cyg Swift Trigger 668097: MASTER-Tunka optical wake up detection
- GRB 151215A: TSHAO optical observations
- GRB151215A: Continued P60 Observations
- GRB151215A: Early optical light curve from pt5m, La Palma
- GRB151215A: Swift/UVOT detection
- GRB 151215A: GROND Detection of the Optical/NIR Afterglow
- GRB151215A: P60 Optical Afterglow Candidate
- LIGO/Virgo G184098: LOFAR follow-up
- GRB151212A: Swift/UVOT observations
- GRB 151212A: GROND Optical Afterglow Candidate
- GRB 151212A: Swift-XRT afterglow detection
- GRB 151212A: Tiled Swift observations
- GRB 151210A: Swift/UVOT Upper Limits
- GRB 151210A: GROND Afterglow Confirmation
- GRB 151210A: Optical afterglow candidate from LCOGT-Cerro Tololo
- GRB 151205C: Optical follow-up observations at Kiso
- GRB 151205B: Deep GROND Upper limits
- GRB 151205B: further Swift-XRT observations
- GRB 151205C: Swift-XRT observations
- GRB 151205C: Tiled Swift observations
- GRB 151205B: MASTER-NET early optical observations
- GRB 151205A: Garching Telescope Upper Limit
- GRB151205B: Initial UVOT observations