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"21109 results found.
- LIGO/Virgo S191222n: No transient candidates in CALET observations
- Swift GRB191228.00: Global MASTER-Net observations report
- Swift GRB191227A: Global MASTER-Net OT detection
- Swift GRB191227.07: Global MASTER-Net observations report
- LIGO/Virgo S191213g: AT2019wxt 10.4m GTC further spectroscopy
- Swift GRB191226.25: Global MASTER-Net observations report
- Swift GRB191226.02: Global MASTER-Net observations report
- Swift trigger 946234/GRB 191226.02 : MASTER obervation
- LIGO/Virgo S191225aq: Global MASTER-Net observations report
- Fermi trigger No 598988276: Global MASTER-Net observations report
- GRB 191221B: ATCA detection of the radio afterglow
- LIGO/Virgo S191205ah: MASTER OT detection
- LIGO/Virgo S191213g: Pan-STARRS monitoring shows PS19hgw (AT2019wxt) to be fading quickly
- LIGO/Virgo S191222n : No significant candidates in FRAM-TAROT-GRANDMA observations
- GRB 191221B: Swift/UVOT Detection
- LIGO/Virgo S191222n: no counterpart candidate in SVOM/GWAC observations
- LIGO/Virgo S191216ap: Upper limits from Insight-HXMT/HE observations
- GRB 191221B: iTelescope optical observations
- GRB 191221B: ALMA detection
- LIGO/Virgo S191216ap: No significant candidates found in Pan-STARRS observations
- GRB 191221B: Zadko observatory - Gingin optical observations
- LIGO/Virgo S191213g : No significant candidates found in GRANDMA citizen science observations
- LIGO/Virgo S191222n: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S191222n: No counterpart candidates in Fermi-LAT observations
- GRB 191221B: MASTER VWFC OT yearly detection
- GRB 191221B: Correction to GCN26551 - VIRT OT observation
- GRB 191221B: VIRT Optical Upper Limits
- GRB 191221B: AGILE/MCAL observations
- LIGO/Virgo S191222n: upper limits from AGILE-GRID observations
- LIGO/Virgo S191222n: upper limits from AGILE/MCAL observations
- LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191222n: INTEGRAL was inactive at the time of the event
- LIGO/Virgo S191222n: No counterpart candidates in HAWC observations
- LIGO/Virgo S191222n: Global MASTER-Net observations report
- Baksan Neutrino Observatory Alert 191222.09: Global MASTER-Net observations report
- GRB 191221B: MASTER OT detection
- Swift GRB 191221B: Global MASTER-Net observations report
- Fermi trigger No 598648473: Global MASTER-Net observations report
- LIGO/Virgo S191216ap: VLA/JAGWAR radio monitoring of the 1-sigma HAWC region
- LIGO/Virgo S191216ap: No radio candidates so far in the VLA/JAGWAR galaxy targeted search
- LIGO/Virgo S191216ap: MASTER optical observation
- LIGO/Virgo S191216ap : No significant candidates in FRAM-TAROT-GRANDMA observations
- LIGO/Virgo S191213g: VLA follow-up of AT2019wxt/PS19hg
- GRB 191220A: Swift/UVOT Upper Limits
- GRB 191220A: AbAO optical observations
- Fermi trigger No 598543714: Global MASTER-Net observations report
- LIGO/Virgo S191213g: AT2019wxt 10.4m GTC spectroscopy
- LIGO/Virgo S191213g : SAO 1-m optical observation of AT2019wxt (PS19hgw)
- GRB 191220A: SAO RAS possible OT detection
- LIGO/Virgo S191213g: DCT observation of AT2019wxt
- Swift GRB191220.56: Global MASTER-Net observations report
- LIGO/Virgo S191220af: Global MASTER-Net observations report
- LIGO/Virgo S191213g: YAHPT Observations of AT2019wxt(PS19hgw)
- LIGO/Virgo S191216ap: Subaru/Hyper Suprime-Cam observations of GW+IceCube+HAWC error region
- LIGO/Virgo S191213g: LBT spectrum of AT2019wxt (PS19hgw) reveals a type IIb supernova
- LIGO/Virgo S191213g: VLT spectrum of AT2019wxt (PS19hgw) - a probable Ib supernova
- LIGO/Virgo S191213g: Lulin Follow-up Observations of AT2019wxt
- LIGO/Virgo S191213g: Swift UVOT/XRT observations of Pan-STARRS1 candidate: PS19hgw
- LIGO/Virgo S191213g: GRAWITA TNG NIR imaging of AT2019wxt (PS19hgw)
- LIGO/Virgo S191216ap, Swift XRT observations: 16 X-ray sources in the HAWC error region search
- LIGO/Virgo S191216ap: No candidates found in J-GEM follow-up observations of HAWC error region
- LIGO/VIRGO S191213g: ePESSTO+ spectroscopy of AT2019wxt (PS19hgw)
- LIGO/VIRGO S191213g: LT spectroscopy of AT2019wxt (PS19hgw)
- LIGO/Virgo S191213g: HCT spectroscopy of PS19hgw / AT2019wxt
- LIGO/Virgo S191216ap: Correction to GCN 26488 (NOWT observations)
- LIGO/Virgo S191213g: No counterpart candidate in the NOWT observations
- LIGO/Virgo S191216ap: No candidates found in CHES observations of HAWC error region
- LIGO/Virgo S191216ap and IceCube neutrino: no counterpart candidates from AGILE-GRID observations
- LIGO/Virgo S191216ap: GRAWITA Loiano observations of HAWC error region
- LIGO/Virgo S191216ap: No transient candidates in CALET observations
- LIGO/Virgo S191216ap: Nanshan follow-up observations
- LIGO/Virgo S191213g: No candidates found in J-GEM follow-up observations
- LIGO/Virgo S191216ap: galaxies consistent with GW + Neutrino + HAWC position
- LIGO/Virgo S191216ap and IceCube neutrino: Swift XRT sources
- LIGO/Virgo S191216ap: IceCube event: MASTER OF detection in GW and Neutrino error field
- LIGO/Virgo S191216ap: No significant counterpart candidates in SAGUARO observations
- LIGO/Virgo S191216ap: HAWC gamma-ray sub-threshold event coincident with LIGO/Virgo and IceCube localizations
- LIGO/Virgo S191213g: Swift UVOT/XRT observations of three ZTF sources
- LIGO/Virgo S191215w : No significant candidates in TAROT - FRAM - GRANDMA observations.
- LIGO/Virgo G191216ap: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191213g: MASTER OT detection in BNS error-box
- LIGO/Virgo S191216ap: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S191215w: No transient candidates in CALET observations
- LIGO/Virgo S191216ap: No Candidates from the Zwicky Transient Facility
- LIGO/Virgo S191216ap: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191216ap: Upper limits from Fermi-GBM Observations
- Fermi-LAT Gamma-ray Observations of IceCube-191215A
- LIGO/Virgo S191216ap: Global MASTER-Net observations report
- LIGO/Virgo S191216ap: No counterpart candidates in HAWC observations
- LIGO/Virgo S191215w: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S191215w: No counterpart candidates in Fermi-LAT observations
- UKIRT photometry of ZTF19acyldun/AT 2019wrt
- LIGO/Virgo S191215w: upper limits from AGILE-GRID observations
- LIGO/Virgo S191215w: upper limits from AGILE/MCAL observations
- LIGO/Virgo S191215w: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S191215w: No counterpart candidates in HAWC observations
- LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191215w: Global MASTER-Net observations report
- IceCube-191215A: not observable by Fermi-GBM
- LIGO/Virgo S191213g: Additional candidates from the Zwicky Transient Facility