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"21112 results found.
- LIGO/Virgo S200225q: No counterpart candidates in HAWC observations
- LIGO/Virgo S200225q: Global MASTER-Net observations report
- LIGO/Virgo S200224ca: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S200225q: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200219ac: No counterpart candidates from Nanshan/NEXT observations
- LIGO/Virgo S200224ca: upper limits from AGILE/GRID observations
- GRB 200224A: RATIR Optical Observations and Confirmation of the Afterglow
- LIGO/Virgo S200224ca: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200224ca: upper limits from AGILE/MCAL observations
- LIGO/Virgo S200224ca: Global MASTER-Net observations report
- GRB 200224A: Swift/UVOT Detection
- GRB 200224A: Tautenburg observations
- GRB 200224A: BOOTES-1 and 1.5m OSN optical observations
- Fermi trigger No 604213554: Global MASTER-Net observations report
- Swift GRB200224.14: Global MASTER-Net observations report
- LIGO/Virgo S200219ac: no counterpart candidate in SVOM/GWAC-F30 observations
- LIGO/Virgo S200219ac: no counterpart candidate in SVOM/GWAC observations
- LIGO/Virgo S200219ac : No significant candidates in TAROT - FRAM - GRANDMA observations.
- GRB 200219C: OAJ afterglow confirmation
- GRB 200219A: UVOT Upper Limits
- GRB 200219C: Mondy and TSHAO optical observations
- GRB 200219C: Nanshan/NEXT optical upper limit and possible host galaxy from PanSTARRS
- LIGO/Virgo S200219ac: No counterpart candidates in KAIT observations
- Fermi trigger No 603949983: Global MASTER-Net observations report
- GRB 200219C: Swift-XRT afterglow detection
- GRB 200219C: DDOTI Observations
- LIGO/Virgo S200213t: Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
- GRB 200219C: Tiled Swift observations
- LIGO/Virgo S200219ac: No transient candidates in CALET observations
- LIGO/Virgo S200219ac: no counterpart candidates in the Swift/BAT observations
- Fermi trigger No 603849435: Global MASTER-Net observations report
- LIGO/Virgo S200219ac: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S200219ac: upper limits from AGILE/GRID observations
- LIGO/Virgo S200213t: Keck/LRIS spectroscopy of counterpart candidates from the Zwicky Transient Facility
- LIGO/Virgo S200219ac: upper limits from AGILE/MCAL observations
- LIGO/Virgo S200219ac: No counterpart candidates in HAWC observations
- LIGO/Virgo S200219ac: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200219ac: Global MASTER-Net observations report
- Swift GRB200219.32: Global MASTER-Net observations report
- LIGO/Virgo (S200213t/IceCube neutrino candidate: No counterpart candidates in the Swift-XRT Observations
- LIGO/Virgo S200213t: No EM counterparts found from continued GECKO observation of host galaxy candidates
- LIGO/Virgo S200213t : No significant candidates in FRAM - OAJ - TAROT - GRANDMA observations
- Further Swift-XRT observations of Swift J0840.7-3516
- GRB 200216B - possible IR counterpart from VLT
- GRB 200216B: z-band limit from NOT
- GRB 200216B: Swift/UVOT Upper Limits
- GRB 200215A: RATIR Optical Observations
- GRB 200216B: Nanshan/NEXT early optical upper limit and possible host galaxy
- Swift GRB200216.56: Global MASTER-Net observations report
- GRB 200215A: UKIRT H-band observations
- LIGO/Virgo S200213t: Updated coverage and candidate list for the Zwicky Transient Facility
- LIGO/Virgo S200213t: CLU/NED Galaxies in the 4-Update Localization Volume
- GRB 200215A: Swift/UVOT Upper Limits
- GRB 200215A: Optical observations form Calar Alto 2.2m
- LIGO/Virgo S200213t: No transient candidates in CALET observations
- LIGO/Virgo S200213t: Lulin Follow-Up Observations
- GRB 200215A: Nanshan/NEXT optical upper limit
- Swift GRB200215.61: Global MASTER-Net observations report
- LIGO/Virgo S200213t: MASTER possible Kilonova candidate in PGC315337
- LIGO/Virgo S200213t: P200 Spectroscopy of ZTF20aanakcd/AT2020cmr
- LIGO/Virgo S200213t: DBSP spectroscopy of AT2020cjb/ZTF20aamvnth, AT2020cja/ZTF20aamvmzj, AT2020cjc/ZTF20aamvoeh
- LIGO/Virgo S200114f: Gemini Spectra of AT 2020vu, AT 2020vw, AT 2020vy, and AT 2020vz
- LIGO/Virgo S200213t: MASTER OT detection in PGC673735
- LIGO/Virgo S200213t: Upper limits from Insight-HXMT/HE observations
- LIGO/Virgo S200213t: No counterpart candidates from Nanshan-0.6m observations
- LIGO/Virgo S200213t: No notable candidates in GOTO imaging
- LIGO/Virgo S200213t: One additional candidate from the Zwicky Transient Facility
- LIGO/Virgo S200213t: No candidates found in J-GEM follow-up observations
- LIGO/Virgo S200213t: More Candidates from the Zwicky Transient Facility
- LIGO/Virgo S200213t: No counterpart candidates in KAIT observations
- LIGO/Virgo S200213t: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S200213t: No Counterparts in DDOTI/OAN Optical Observations
- LIGO/Virgo S200213t: MANGROVE catalog galaxy ranking
- LIGO/Virgo S191213g: AT2019wxt Wendelstein optical observations
- LIGO/Virgo S200213t: upper limits from AGILE/GRID observations
- LIGO/Virgo S200208q : No significant candidates in TAROT - FRAM - GRANDMA observations
- LIGO/Virgo S200208q: no counterpart candidate in SVOM/C-GFT observations
- LIGO/VIRGO S200213t: upper limits from AGILE/MCAL observations
- LIGO/Virgo S200213t: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S200213t: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200213t: NED Galaxies in the 90% Localization Volume
- LIGO/Virgo S200213t: Global MASTER-Net observations report
- ZTF20aajnksq: Upper limits from Konus-Wind observations
- Fermi trigger No 603197394: Global MASTER-Net observations report
- GRB 200131A: Tautenburg observations
- LIGO/Virgo S200208q: No counterpart candidates in KAIT observations
- LIGO/Virgo S200208q: No counterpart candidates in Fermi-LAT observations
- GRB 200205B: Chilescope optical observations
- LIGO/Virgo S200129m: Upper limits from Insight-HXMT/HE observations
- LIGO/Virgo S200208q: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200208q: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S200208q: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S200208q : upper limits from AGILE/GRID observations
- LIGO/Virgo S200208q: upper limits from AGILE/MCAL observations
- LIGO/Virgo S200208q: Global MASTER-Net observations report
- LIGO/Virgo S200208q: No counterpart candidates in HAWC observations
- Fermi trigger No 602817262: Global MASTER-Net observations report
- Fermi trigger No 602731380: Global MASTER-Net observations report
- Swift GRB200207.13: Global MASTER-Net observations report
- GRB 200205B: Swift/UVOT Detection