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 151205B: Swift-XRT observations
- GRB 151205A: Swift/UVOT Upper Limits
- LIGO/Virgo G184098: Results of of 2nd epoch of ASKAP follow-up
- GRB 151122A: Further Swift-XRT observations, no afterglow detected.
- GRB 151127A: Swift/UVOT Upper Limits
- GRB 151127A: GROND K-band upper limit
- GRB 151127A: LCOGT-SSO optical upper limits
- GRB 151122A: Swift/UVOT Observations
- GRB 151122A: Swift-XRT observations
- GRB 151122A: Swift ToO observations
- GRB 151027A: Maidanak optical observations
- GRB 151120A: Swift-XRT afterglow detection
- GRB 151120A: Swift ToO observations
- GRB 151120A: GROND optical/NIR afterglow
- LIGO/Virgo G194575: Fermi GBM Observations
- 610 MHz detection of GRB 151027A with the GMRT
- GRB 151118A: Early optical limit from pt5m, La Palma
- GRB 151027A: SAO RAS and Mt. Terskol observations
- GRB 151118A: Swift/UVOT Upper Limits
- GRB GRB 151118A: MASTER-NET optical observations
- GRB 151118A: Optical observations from OSN
- GRB151027A; Optical observations
- GMRT radio detection of GRB 151027A
- GRB 151114A: GROND Detection of the Optical/NIR Afterglow Candidate
- GRB 151112A: GROND photometric redshift and i'-band prediction
- GRB 151114A: Swift/UVOT Detection
- GRB 151114A: LCOGT-FTS afterglow observations
- GRB 151111A: GROND confirmation of the afterglow and photometric redshift estimate
- GRB 151112A: Swift/UVOT Upper Limits
- GRB 151112A: GROND Detection of the Optical/NIR Afterglow Candidate
- GRB 151112A: initial UVOT observations
- GRB 151112A: Swift-XRT observations
- GRB 151111A: Swift/UVOT upper limits
- GRB 151111A: GROND marginal detection of a afterglow candidate
- LIGO/Virgo G194575: VLA follow-up
- GRB 151111A: LCOGT-FTS afterglow observations
- GRB 151107B: MASTER-NET OT detection inside the FERMI error box
- GRB 151027A: continued Mondy optical observations
- LIGO/Virgo G194575: Liverpool Telescope observations of iPTF-15dld and iPTF-15dni
- LIGO/Virgo G194575: La Silla QUEST, Pan-STARRS and PESSTO observations of iPTF15dld
- LIGO/Virgo G194575: Swift observations if iPTF15dld
- GRB 151027A: Hankasalmi optical observations
- LIGO/Virgo G194575: INAF-TNG/Asiago Telescope follow-up of iPTF15dld
- GRB 151107A: MASTER-NET optical observations
- LIGO/Virgo G194575: INAF-Asiago Telescope further analysis of iPTF candidates
- Swift-BAT triggers are disabled
- LIGO/Virgo G194575: INAF-Asiago Telescope follow-up of iPTF candidates
- LIGO/Virgo G194575: VLA follow-up
- GRB 151027A: Mondy optical observations
- GRB 150910A: CrAO optical observations
- GRB 151027A: Correction to GCN 18519
- GRB 151031A: GROND observation
- LIGO/Virgo G194575: LT Spectroscopy of iPTF candidates
- GRB 151031A: Swift/UVOT Detection
- GRB 151031A: VLT/X-shooter optical counterpart and redshift
- GRB 151027A: optical follow-up observations
- GRB 151027A: Continued P60 Monitoring
- LIGO/Virgo G194575: INAF-TNG follow-up of iPTF15dkm and iPTF15dlj
- GRB 151029A: Swift/UVOT Detection
- GRB 151029A: LCOGT-FTS afterglow observations
- GRB 151027B: Swift UVOT detection
- LIGO/Virgo G194575: VLA follow-up
- GRB 151027A: MAXI/GSC detection
- GRB 151029A VLT/X-shooter redshift
- GRB 151029A: GROND afterglow observations
- GRB 151027A: SAO RAS optical observations
- GRB 151027B: LCOGT FTN afterglow observations
- GRB 151027A: NOT optical and NIR observations
- GRB 151027A: T100 observations
- GRB 151027B: Swift/UVOT Upper Limits
- GRB 151027A : Xinglong TNT optical observation
- GRB 151027A: continued GMG observation
- GRB 151027B: RATIR Observations
- GRB 151027B: MASTER-NET early OT detection
- GRB 151027A: LCOGT-McDonald afterglow observations
- GRB 151027A: VLA detection
- GRB 151027B: GROND Optical/NIR Afterglow Detection
- GRB 151027B: VLT/X-shooter redshift
- GRB 151027A: THO optical observations
- GRB 151027A: UVOT Observations
- GRB 151027B: NOT optical afterglow candidate
- LIGO/Virgo G194575: iPTF Optical Transient Candidates
- GRB 151027A: Early RAPTOR Observations
- LIGO/Virgo G194575: MASTER Optical Inspection
- GRB 151027A: GMG observation
- LIGO/Virgo G194575: Swift observations of LSQ15bjb
- LIGO/Virgo G194575: GROND multi-color observations
- GRB 151027A: Weihai optical observations
- LIGO/Virgo G194575: further Pan-STARRS observations of the RA=1hr localisation region
- GRB 151027A: KAIT optical afterglow confirmation
- LIGO/Virgo G194575: ASKAP followup
- LIGO/Virgo G194575: INAF-TNG follow-up of LSQ15bjb
- LIGO/Virgo G194575 : La Silla - QUEST followup
- GRB 151021A: Skynet PROMPT-CTIO/DSO17 observations of the optical afterglow
- LIGO/Virgo G194575: Near-infrared follow-up with OAO-WFC
- LIGO/Virgo G194575: Kanata/J-GEM optical follow-up
- LIGO/Virgo G194575: Pi of the Sky observations
- LIGO/Virgo G194575: MAXI/GSC observations
- LIGO/Virgo G194575: Swift observations
- GRB 151022A: OSN optical upper limit