GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"3039 results found.
- Baksan Neutrino Observatory Alert 200408.26: Global MASTER-Net observations report
- Fermi GRB 200407B: Global MASTER-Net observations report
- GRB 200404A: Fermi GBM Final Localization
- GRB 200404A: BALROG localization (Fermi Trigger 607712227 / GRB 200404706)
- Fermi GRB 200403B: Global MASTER-Net observations report
- Fermi GRB 200403A: Global MASTER-Net observations report
- GRB 200403C: Fermi GBM Final Real-time Localization
- LIGO/Virgo S200316bj: Upper limits from Konus-Wind observations
- Fermi GRB 200402C: Global MASTER-Net observations report
- Fermi GRB 200401A: Global MASTER-Net observations report
- IPN triangulation of GRB 200327A (short)
- Fermi trigger No 607035413: Global MASTER-Net observations report
- Fermi trigger No 606918292: Global MASTER-Net observations report
- Fermi trigger No 606840801: Global MASTER-Net observations report
- GRB 200324A:: TSHAO optical upper limit
- Fermi trigger No 606681997: Global MASTER-Net observations report
- LIGO/Virgo S200316bj : No significant candidates in TAROT - FRAM - GRANDMA observations.
- LIGO/Virgo S200316bj: Upper limits from Insight-HXMT/HE observations
- Konus-Wind observation of GRB 200313B
- LIGO/Virgo S200316bj: no counterpart candidate in SVOM/GWAC observations
- LIGO/Virgo S200316bj: Upper limits from CALET observations
- LIGO/Virgo S200316bj: No neutrino candidates at Pierre Auger Observatory
- LIGO/Virgo S200316bj: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S200316bj: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S200316bj: No counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
- LIGO/Virgo S200316bj: upper limits from AGILE/GRID observations
- LIGO/Virgo S200316bj: upper limits from AGILE/MCAL observations
- LIGO/Virgo S200316bj: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200316bj : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S200316bj: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 200313B (short)
- SGR Swift J1818.0-1607: Swift-BAT refined analysis
- Fermi trigger No 605789837: Global MASTER-Net observations report
- GRB 200313B: Fermi GBM Final Real-time Localization
- Fermi trigger No 605756501: Global MASTER-Net observations report
- Fermi trigger No 605309224: Global MASTER-Net observations report
- GRB 200306A: Swift-BAT refined analysis
- LIGO/Virgo S200302c : No significant candidates in FRAM - TAROT - GRANDMA observations.
- GRB 200303A: Swift-BAT refined analysis
- GRB 200303A: Swift detection of a burst
- LIGO/Virgo S200302c: No counterpart candidates in KAIT observations
- LIGO/Virgo S200302c: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S200225q : No significant candidates in TAROT - FRAM - GRANDMA observations.
- GRB 200228B: Swift-BAT refined analysis
- LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates
- GRB 200228B: Swift detection of a burst
- GRB 200227A: Swift-BAT refined analysis
- GRB 200219A: ATCA 5/9 GHz radio observations
- LIGO/Virgo S200224ca : No significant candidates in TAROT - FRAM - GRANDMA observations
- Konus-Wind observation of GRB 200219C
- LIGO/Virgo S200225q: no counterpart candidate in SVOM/GWAC observations
- LIGO/Virgo S200224ca: No counterpart candidates in KAIT observations
- Fermi trigger No 604231129: Global MASTER-Net observations report
- LIGO/Virgo S200224ca: Coverage and upper limits from MAXI/GSC observations
- 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.
- IPN triangulation of GRB 200219B (inconsistent with the LIGO/Virgo S200219ac)
- GRB 200219C: CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo S200219ac: No counterpart candidates in KAIT observations
- GRB 200219C: Fermi GBM detection
- GRB 200219C: Fermi-LAT detection
- GRB 200219C: Fermi GBM Final Real-time Localization
- GRB 200219A: Swift-XRT refined Analysis correction
- GRB 200219A: Swift-XRT refined Analysis
- GRB 200216B: Swift-BAT refined analysis
- LIGO/Virgo S200213t : No significant candidates in FRAM - OAJ - TAROT - GRANDMA observations
- LIGO/Virgo S200213t: No candidates found in J-GEM follow-up observations
- LIGO/Virgo S200213t: No counterpart candidates in KAIT observations
- LIGO/Virgo S200213t: No Counterparts in DDOTI/OAN Optical 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 S200208q: No counterpart candidates in KAIT observations
- Fermi trigger No 602817262: Global MASTER-Net observations report
- GRB 200205B: Swift-BAT refined analysis
- Swift J0840.7-3516 (AKA GRB 200205A): Swift-BAT refined analysis
- ZTF20aajnksq: Gemini-North r-band photometry
- GRB 200201A: Fermi GBM Final Real-time Localization
- IPN triangulation of GRB 200130B
- LIGO/Virgo S200128d: no counterpart candidate in SVOM/GWAC observations
- LIGO/Virgo S200128d : No significant candidates in FRAM - TAROT - GRANDMA observations
- GRB 200130A: Fermi GBM Final Real-time Localization
- LIGO/Virgo S200128d: No counterpart candidates in KAIT observations
- Fermi-LAT-ANTARES coincidence
- Fermi trigger No 601729856: Global MASTER-Net observations report
- Fermi trigger No 601677816: Global MASTER-Net observations report
- LIGO/Virgo S200114f : No significant candidates in TAROT - FRAM - GRANDMA observations
- LIGO/Virgo S200115j : No significant candidates in TAROT - FRAM - GRANDMA observations
- LIGO/Virgo S200105ae: More candidates from the Zwicky Transient Facility
- IceCube Alert 200117.46: Global MASTER-Net observations report
- LIGO/Virgo S200115j: Swift-XRT sources
- LIGO/Virgo S200114f: ZTF Forced Photometry of the Swift Source S200114f_X2
- LIGO/Virgo S200112r : No significant candidates in TAROT - FRAM - GRANDMA observations.
- LIGO/Virgo S200115j: no counterpart candidate in SVOM/GWAC observations
- Baksan Neutrino Observatory Alert 200116.22: Global MASTER-Net observations report
- GRB 200115A: Swift-BAT refined analysis
- Swift GRB200115.49: Global MASTER-Net observations report
- LIGO/Virgo S200114f: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
- GRB 200109A: Fermi GBM observation
- LIGO/Virgo S200105ae : No significant candidates in TAROT - FRAM - GRANDMA observations.