GCN Circulars
GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"16289 results found.
- LIGO/Virgo S190814bv: Palomar 200-in spectroscopic redshift and host galaxy properties of ASKAP source AT2019osy
- LIGO/Virgo S190814bv: Optical non-detection of radio source AT2019osy from CFHT
- Fermi GBM-190816: Eight additional candidates from the Zwicky Transient Facility
- LIGO/Virgo S190814bv: DECam-GROWTH detection of an optical counterpart to the radio source AT2019osy
- LIGO/Virgo S190814bv: Final list of candidates from the DESGW coadd analysis from the week long search campaign
- LIGO/Virgo S190814bv: CFHTphotometryof AT2019npv
- LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019npw and AT2019num
- LIGO/Virgo S190814bv : Magellan IMACS Spectrum of AT2019npv classified as a Type Ib supernova
- LIGO/Virgo S190814bv: SALT optical spectrum of candidate DG19aqbkc
- GRB 190824A: Swift/UVOT Upper Limits
- LIGO/Virgo S190814bv: No radio counterpart to DG19wxnjc/AT2019npv in ASKAP observations
- LIGO/Virgo S190814bv: Keck NIRES spectroscopy of DG19wxnjc/AT2019npv
- LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv
- GRB 190821A: Swift/UVOT Upper Limits
- GRB 190821A: MASTER VWFC syncronous optical observations
- Fermi GBM-190816: MASTER-Net optical observation report
- LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
- LIGO/Virgo S190814bv: a potential faint optical counterpart in CFHT imaging
- LIGO/Virgo S190814bv: No Optical Counterpart Candidates in Second-Epoch Lick/KAIT Observations
- GRB 190821A: T60 Les Makes optical detection of the afterglow
- Fermi GBM-190816: Four additional candidates from the Zwicky Transient Facility
- LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019noq and AT2019ntn
- Fermi GBM-190816: ZTF19abqanpy 10.4m GTC spectroscopy
- LIGO/Virgo S190814bv: AT2019nqq 10.4m GTC spectroscopy
- LIGO/Virgo S190814bv: RATIR Optical observations of DECam transients
- LIGO/Virgo S190814bv: Additional candidates identified in DECam images by the DECam-GROWTH team
- LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
- LIGO/Virgo S190814bv: SOAR spectroscopy of 2 DESGW candidates
- LIGO/Virgo S190814bv: no candidates from optical imaging of selected galaxies at the NOT
- LIGO/Virgo S190814bv: New candidates from DECam DESGW difference imaging search
- LIGO/Virgo S190814bv: GROND imaging of candidate galaxies
- S190814bv: MASTER analysis of DECam-GROWTH candidates
- LIGO/Virgo S190814bv: No candidates identified in DECam data by visual inspection
- LIGO/Virgo S190814bv: des-gw190814b is a moving object
- LIGO/Virgo S190814bv: No Counterparts in DDOTI/OAN Optical Observations
- LIGO/Virgo S190814bv: No counterpart candidates in TOROS observations
- LIGO/Virgo S190814bv: no counterpart candidates in Keck I MOSFIRE imaging
- LIGO/Virgo S190814bv: MeerLICHT coverage second preliminary skymap
- LIGO/Virgo S190814bv Global MASTER-Net optical observations
- LIGO/Virgo S190814bv: no candidates from GOTO imaging observations
- LIGO/Virgo S190814bv: Candidates found in initial DESGW search
- LIGO/Virgo S190814bv: Nordic Optical Telescope imaging of selected galaxies
- FRB 190806: MASTER optical observation
- LIGO/Virgo S190728q: New optical candidates from the DESGW program
- LIGO/Virgo S190728q: AT2019lvw 10.4m GTC spectroscopy
- LIGO/Virgo S190728q: AT2019lzc 10.4m GTC spectroscopy
- GRB 190731A: Swift/UVOT Upper Limits
- GRB 190731A: no OT detected by MASTER
- IceCube 190730A: No counterpart candidates or blazar activity in GOTO observations
- LIGO/Virgo S190728q: AT2019lzt 10.4m GTC spectroscopy
- LIGO/Virgo S190728q: ZTF Forced Photometry for PS1 and DECam-GROWTH optical candidates, and a note on DECam Photometry from GCN 25215
- IceCube-190730A: MASTER optical observation
- LIGO/Virgo S190728q: MITSuME Okayama and Bisei Follow-Up of ZTF19abjethn (AT2019lvs)
- LIGO/Virgo S190728q: Optical transients from Pan-STARRS coverage during first 2 nights
- LIGO/Virgo S190728q: Optical Counterpart Candidates from DECam-GROWTH
- LIGO/Virgo S190728q: ZTF19abjethn TShAO and NUTTelA-TAO optical observations / classification
- LIGO/Virgo S190728q: Classification of AT2019lvs/ZTF19abjethn as a CV
- LIGO/Virgo S190728q: Update on Sky-Localization and Source-Classification
- LIGO/Virgo S190728q: LCO Follow-Up of ZTF19abjethn (AT2019lvs)
- LIGO/Virgo S190728q: Pan-STARRS detection of the transient AT2019lvs/ZTF19abjethn 18hrs before S190728q
- LIGO/Virgo S190728q: Identification of a Faint Blue Static Source at the Location of ZTF19abjethn
- LIGO/Virgo S190728q: Photometric Redshift and Stellar Mass Estimates for the Potential Host Galaxy of Optical Counterpart Candidate ZTF19abjethn
- LIGO/Virgo S190728q: Optical Candidate from the Zwicky Transient Facility ZTF19abjethn
- LIGO/Virgo S190718y: Classification of AT 2019lqm / Gaia19dcs as a Type Ia Supernova
- LIGO/Virgo S190718y: Classification of AT 2019lqn / Gaia19dct as a Type Ia Supernova
- GRB 190719C: optical afterglow confirmation
- LIGO/Virgo S190720a: No counterpart candidates in CNEOST observations
- GRB 190719C: Swift/UVOT Upper Limits
- LIGO/Virgo S190718y: No counterpart candidates in CNEOST
- GRB 190719C: NOT candidate optical afterglow and host
- GRB 190718A: Swift/UVOT Upper Limits
- GRB 190718A: FRAM-Auger optical limit
- LIGO/Virgo S190707q: No counterpart candidates in the CNEOST
- GRB 190706B: Swift/UVOT Detection
- GRB 190627A: Discovery Channel Telescope late time observations
- GRB 190530A: Observation of the afterglow by NOEMA
- GRB 190701A: Swift/UVOT Upper Limits
- GRB190701A: No candidates/counterpart in optical follow-up from GROWTH-India Telescope
- GRB 190630B: Tien Shan and Koshka Zeiss-1000 optical upper limits
- GRB 190630C: ISON-Castelgrande optical upper limit
- GRB 190701A: COATLI Optical Observations
- GRB 190630C: Swift/UVOT Upper Limits
- GRB 190630C: KAIT Optical Upper Limit
- GRB 190630B: Swift/UVOT Upper Limits
- GRB 190630B: KAIT Optical Afterglow Confirmation
- GRB 190627A: VLT/FORS2 spectroscopic redshift
- GRB Swift Trigger 912102: KAIT Optical Afterglow Candidate
- GRB 190627A: Koshka Zeiss-1000 optical counterpart observations
- GRB 190627A : Xinglong 2.16m optical observation
- GRB 190627A: GMG observation at the second epoch
- GRB 190627A: NOT optical observations
- GRB 190627A: Optical imaging by D50 from Ondrejov
- GRB 190627A: Optical imaging and spectroscopy from Calar Alto
- GRB 190627A: NUTTelA-TAO optical counterpart observations
- GRB 190627A: GMG observation
- GRB 190627A: MASTER optical counterpart observation
- GRB190627A: VIRT Afterglow observation
- GRB 190627A: Montarrenti Observatory optical detection
- GRB 190627A: NUTTelA-TAO optical observations
- Swift trigger 911102: D50 optical limit