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.
- IceCube Alert 191215.47: Global MASTER-Net observations report
- LIGO/Virgo S191213g: Upper limits from Insight-HXMT/HE observations
- LIGO/Virgo S191213g: LCOGT photometry of ZTF19acymaru/AT2019wnh
- LIGO/Virgo S191213g: Lulin Follow-up Observations of ZTF19acykzsk/AT2019wqj
- LIGO/Virgo S191213g: Liverpool Telescope spectroscopy of ZTF candidates
- LIGO/Virgo S191213g: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S191213g: No transient candidates in CALET observations
- Fermi trigger No 597955752: Global MASTER-Net observations report
- LIGO/Virgo S191213g: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191213ai: Global MASTER-Net observations report
- LIGO/Virgo S191213g: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S191213g: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S191213g: upper limits from AGILE-GRID observations
- LIGO/Virgo S191213g: upper limits from AGILE-MCAL observations
- Fermi trigger No 597909938: Global MASTER-Net observations report
- LIGO/Virgo S191213g: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191213g: Global MASTER-Net observations report
- LIGO/Virgo S191212q: Global MASTER-Net observations report
- Baksan Neutrino Observatory Alert 191211.1: Global MASTER-Net observations report
- Possible HAWC-detected GRB 191210A: Fermi-LAT Upper Limits
- Possible HAWC-detected GRB 191210A: Swift-XRT observations
- Fermi trigger No 597737032: Global MASTER-Net observations report
- LIGO/Virgo S191205ah: no counterpart candidate in SVOM/GWAC observations
- LIGO/Virgo S191205ah : No significant candidates in FRAM - TAROT – GRANDMA observations
- LIGO/Virgo S191205ah: MITSuME Observation of MASTER OT J123123.61-043847.2
- LIGO/Virgo S191204r: GRAWITA VST-ESO PARANAL observations.
- LIGO/Virgo S191205ah: MASTER OT detection
- IceCube-191204A : Upper limits from Insight-HXMT/HE observations
- LIGO/Virgo S191205ah: Upper limits from Insight-HXMT/HE observations
- LIGO/Virgo S191204r: Upper limits from Insight-HXMT/HE observations
- Fermi-LAT Gamma-ray Observations of IceCube-191204A
- LIGO/Virgo S191205ah: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S191205ah: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191129u : No significant candidates in FRAM-TAROT-GRANDMA observations.
- LIGO/Virgo S191204r: No significant candidates in FRAM-TAROT-GRANDMA observations.
- LIGO/Virgo S191205ah: SAGUARO observations and identification of an optical candidate
- LIGO/Virgo S191205ah: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S191204r: No transient candidates in CALET observations
- LIGO/Virgo S191204r: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191205ah: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191205ah: upper limits from AGILE-MCAL observations
- LIGO/Virgo S191205ah: No counterpart candidates in HAWC observations
- LIGO/Virgo S191205ah: Global MASTER-Net observations report
- LIGO/Virgo S191204r: no counterpart candidates in the Swift/BAT observations
- GRB 191130A: Swift-XRT observations
- IceCube-191204A: Upper limits from Fermi-GBM Observations
- IceCube Alert 191204.95: Global MASTER-Net observations report
- LIGO/Virgo S191204r: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191204r: upper limits from AGILE-GRID observations
- LIGO/Virgo S191204r: upper limits from AGILE-MCAL observations
- LIGO/Virgo S191204r: Global MASTER-Net observations report
- GRB 191130A: Swift ToO observations
- Fermi trigger No 597049044: Global MASTER-Net observations report
- LIGO/Virgo S191129u: No transient candidates in CALET observations
- Fermi trigger No 596786686: Global MASTER-Net observations report
- Fermi trigger No 596808579: Global MASTER-Net observations report
- LIGO/Virgo S191129u: Upper limits from Insight-HXMT/HE observations
- LIGO/Virgo S191129u: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191129u: No counterpart candidates in HAWC observations
- LIGO/Virgo S191129u: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191129u: upper limits from AGILE/GRID observations
- LIGO/Virgo S191129u: upper limits from AGILE/MCAL observations
- LIGO/Virgo S191129u: Global MASTER-Net observations report
- Fermi trigger No 596690552: Global MASTER-Net observations report
- Baksan Neutrino Observatory Alert 191128.17: Global MASTER-Net observations report
- Baksan Neutrino Observatory Alert 191127.25: Global MASTER-Net observations report
- IceCube-191122A: Not observable by Fermi-GBM
- Fermi trigger No 596387570: Global MASTER-Net observations report
- Baksan Neutrino Observatory Alert 191124.13: Global MASTER-Net observations report
- Fermi-LAT Gamma-ray Observations of IceCube-191122A
- LIGO/Virgo S191124be: Global MASTER-Net observations report
- GRB 191123A: Swift/UVOT further analysis
- GRB 191123A: Swift/UVOT detection
- IceCube-191122A: INTEGRAL was inactive at the time of the event
- IceCube-191122A: Global MASTER-Net observations report
- GRB 191122A: Swift/UVOT Upper Limits
- GRB 191122A: BOOTES-4/MET optical limit
- GRB 191122A: CHES Optical Observations
- LIGO/Virgo S191120aj: Global MASTER-Net observations report
- Fermi-LAT Gamma-ray Observations of IceCube-191119A
- IceCube-191119A: Upper limits from Fermi-GBM Observations
- Swift GRB191115A: Global MASTER-Net observations report
- LIGO/Virgo S191110af: Upper limits from Konus-Wind observations
- Announcing the GW Treasure Map
- LIGO/Virgo S191110af: Potential pulsar counterparts
- GRB 191031D: CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo S191110af: Swift XRT observations, no secure afterglow found
- LIGO/Virgo S191110af: Upper limits from CALET observations.
- LIGO/Virgo S191110af: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S191110af: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191110af: upper limits from AGILE/MCAL observations
- LIGO/Virgo S191110af: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S191110af: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191110af: Global MASTER-Net observations report
- LIGO/Virgo S191109d: No significant candidates in FRAM-TAROT-GRANDMA observations
- LIGO/Virgo S191110x: Global MASTER-Net observations report
- LIGO/Virgo S191109d: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191105e: No significant candidates in FRAM-TAROT-GRANDMA observations
- LIGO/Virgo S191105e: Upper limits from Insight-HXMT/HE observations
- LIGO/Virgo S191109d: no counterpart candidates in the Swift/BAT observations