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"21093 results found.
- LIGO/Virgo S190425z: KPED Follow-Up of ZTF transients
- LIGO/Virgo S190426c: GRAWITA transients from Asiago Schmidt wide field observations
- LIGO/Virgo S190425z: DECam Observations of the UVOT Candidate Region
- LIGO/Virgo S190426c: Continued LOAO Observation
- LIGO/Virgo S190425z: VISTA K-band observations of the Swift/UVOT Transient
- GRB 190427A: Swift/UVOT Upper Limits
- LIGO/Virgo S190426c: Additional Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190426c: Continued infrared wide-field search with Palomar Gattini-IR
- LIGO/Virgo S190426c: OAJ-GRANDMA observation report
- LIGO/Virgo S190425z: MASTER explanation of the nature of an optical flash detected by a Swift as a short flare on a fast-moving WISE brown
- LIGO/Virgo S190425z: No i-band detection of the Swift/UVOT transient in SkyMapper observations
- LIGO/Virgo S190426c: ASAS-SN observations
- LIGO/Virgo S190425z: Spectroscopic observations of two ZTF candidates with SOAR
- LIGO/Virgo S190425z: KPED Follow-Up of ZTF transients
- LIGO/Virgo S190425z: SVOM/GWAC-F60A observations
- LIGO/Virgo S190425z: No Optical Detection of the Swift/UVOT Transient in ASAS-SN observations hours before and after discovery
- LIGO/Virgo S190425z: Potential host galaxy of UVOT candidate counterpart found in BLISS
- LIGO/Virgo S190425z: Additional Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190426c: DDOTI/OAN Optical Observations
- LIGO/Virgo S190425z: ASAS-SN observations
- LIGO/Virgo S190425z: GROWTH-India observations of the Swift/UVOT transient
- Correction to GCN Circular 24301: LIGO/Virgo S190425z: Lulin observations of the Swift/UVOT transient
- LIGO/Virgo S190425z: ZTF photometry of the UVOT transient candidate hours before discovery
- LIGO/Virgo S190425z: Lulin observations of the Swift/UVOT transient
- LIGO/Virgo S190426c: RATIR Optical and NIR Observations of Galaxies
- LIGO/Virgo S190426c: J-GEM optical/NIR follow-up observations
- LIGO/Virgo S190426c: COATLI Optical Observations of Galaxies
- LIGO/Virgo S190425z: Further confirmation for the classification of PS19qp/AT 2019ebq as a supernova
- Fermi GRB190427.19 Global MASTER-Net observations report
- LIGO/Virgo S190426c: MMT Follow-Up Observations
- LIGO/Virgo S190426c: GOTO optical coverage - no notable counterparts
- GRB 190427A: Lick/Nickel telescope optical observations
- LIGO/Virgo S190426c: Lick/KAIT Follow-Up Observations
- GRB 190427A: COATLI Optical Observations
- LIGO/Virgo S190426c: CNEOST Optical Observations
- LIGO/Virgo S190425z: CNEOST Optical Observations
- LIGO/Virgo S190426c: Infrared Wide-field Search with Palomar Gattini-IR
- LIGO/Virgo S190426c: Optical Wide-field Search with the Zwicky Transient Facility
- GRB 190427A: RATIR Optical and NIR Observations
- LIGO/Virgo S190426c: Nanshan/NEXT Observation of Galaxies
- LIGO/Virgo S190426c: Hobby-Eberly Telescope VIRUS observations of target galaxies.
- LIGO/Virgo S190426c: CALET Observations
- LIGO/Virgo S190426c: Imaging confirmation and host spectroscopy of DG19vkgf
- LIGO/Virgo S190425z: Lulin Observations of Counterpart Search
- LIGO/Virgo S190426c: Swift-XRT sources
- GRB 190427A: BOOTES-1 and BOOTES-5/JGT early follow-up observations
- LIGO/Virgo S190425z: BOOTES-5/JGT observations of galaxies
- LIGO/Virgo S190425z - ePESSTO+ spectrum of candidate PS19qu
- LIGO/Virgo S190426c: Red and blue transients identified with DECam
- LIGO/Virgo S190425z: Lijiang 2.4-m Telescope Follow-up Observations
- GRB 190427A: NOT optical observations
- GRB 190427A: Swift-XRT observations
- Swift GRB190427.19 Global MASTER-Net observations report
- LIGO/Virgo S190425z: ANU 2.3m early observations of ZTF19aarykkb
- LIGO/Virgo S190426c: MAXI/GSC Observations
- LIGO/Virgo S190426c: Public DECam Observations
- LIGO/Virgo S190425z: GRANDMA follow-up observations with Les Makes-T60, AZT-8 and Abastumani-T70
- LIGO/Virgo S190426c: STARE2 simultaneous L-band radio observations
- LIGO/Virgo S190425z: GRAWITA LBT spectroscopic observations
- LIGO/Virgo S190426c: Fermi GBM Observations
- LIGO/Virgo S190426c: AGILE-GRID Observations
- LIGO/Virgo S190425z: Further MMT Follow-Up Observations
- Baksan Neutrino Observatory Alert 190405.62: Global MASTER-Net:LIGO/Virgo S190425z: PanSTARR OT AT2019ebq/PS19qp
- LIGO/Virgo S190425z: COATLI Observations of Galaxies
- LIGO/Virgo S190425z: RATIR Observations of Galaxies
- LIGO/Virgo S190426c Global MASTER-Net observations report
- LIGO/Virgo S190425z: YAHPT Optical Observation
- LIGO/Virgo S190425z: Nearby Galaxies in the Updated Localization Volume
- LIGO/Virgo S190425z: J-GEM spectroscopic observations of AT2019ebq/PS19qp with Subaru/FOCAS
- LIGO/Virgo S190425z: GROND observations of AT2019ebq/PS19qp
- LIGO/Virgo S190425z: TAROT-GRANDMA observation report
- LIGO/Virgo S190425z: AMI-LA radio observations of two ZTF afterglow candidates.
- LIGO/Virgo S190425z: GOTO observations
- LIGO/Virgo S190425z: LWA1 observations
- LIGO/Virgo S190425z: DCT ZTF19aarykkb spectroscopy
- LIGO/Virgo S190425z: CALET Observations
- LIGO/Virgo S190425z - ePESSTO+ spectrum of PS19qp shows red featureless source at z=0.037
- LIGO/Virgo S190425z - ePESSTO+ NTT spectrum of candidate PS19qo
- LIGO/Virgo S190425z: Swope follow-up observations
- LIGO/Virgo S190425z - ePESSTO+ NTT observations
- LIGO/Virgo S190425z: Pan-STARRS observations and transients in the skymap
- LIGO/Virgo S190425z: ZTF19aarzaod WHT spectroscopy
- LIGO/Virgo S190425z: GRAWITA TNG observations of ZTF19aarzaod
- LIGO/Virgo S190425z: ZTF19aarykkb Imaging from Las Cumbres Observatory
- LIGO/Virgo S190425z: Liverpool Telescope spectroscopy of ZTF19aarykkb
- LIGO/Virgo S190425z - HCT spectroscopy
- LIGO/Virgo S190425z: STARE2 simultaneous L-band radio observations
- LIGO/Virgo S190425z: KPED Follow-Up Observations
- LIGO/Virgo S190425z: ATLAS observations of the S190425z skymap
- LIGO/Virgo S190425z: OVRO-LWA simultaneous low frequency radio observations of localization region
- LIGO/Virgo S190425z: CLU/NED Galaxies in the Localization Volume
- LIGO/Virgo S190425z: Lulin Follow-Up Observations
- LIGO/Virgo S190425z: J-GEM optical follow-up observations with Subaru/FOCAS
- LIGO/Virgo S190425z: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190425z: Xinglong/Schmidt follow-up observations
- LIGO/Virgo S190425z: Palomar Gattini-IR wide-field infrared follow-up
- LIGO/Virgo S190425z: AGILE-GRID Observations
- LIGO/Virgo S190425z: Fermi GBM Observations
- LIGO/Virgo S190425z: MMT Follow-Up Observations
- LIGO/Virgo S190425z: INTEGRAL IBIS prompt observation