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"
4714 results found.
- GRB 230728A: Swift detection of a burst
- GRB 230727A: Swift/BAT-GUANO detection of a burst
- GRB 230727A: Fermi GBM Final Real-time Localization
- IBAS trigger number 10337: not a real GRB
- IPN triangulation of GRB 230723A (short)
- IceCube Alert 230724.08: Global MASTER-Net observations report
- Fermi trigger No 711805358: Global MASTER-Net observations report
- GRB 230703A detected with multiple GRID detectors
- GRB 230707A: Fermi GBM Detection
- Fermi GRB 230707A: Global MASTER-Net observations report
- GRB 230707A: Fermi GBM Final Real-time Localization
- LVK S230619bd/GBM-230619: Upper limits from a two-week IceCube neutrino search
- LIGO/Virgo/KAGRA S230627c: GRANDMA observations of galaxies and ZTF counterpart candidates
- AT2023lcr (ATLAS23msn/ZTF23aaoohpy): ALMA 100 GHz Detection
- ZTF23aaoohpy /AT2023lcr: TNG NIR detection
- LIGO/Virgo/Kagra S230627c: NED Galaxies in the Localization Volume
- LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S230622e: Global MASTER-Net observations report
- LIGO/Virgo S230621bq: Global MASTER-Net observations report
- LIGO/Virgo S230621ad: Global MASTER-Net observations report
- LIGO/Virgo S230620ad: Global MASTER-Net observations report
- LIGO/Virgo S230620au: Global MASTER-Net observations report
- LIGO/Virgo S230620z: Global MASTER-Net observations report
- LIGO/Virgo S230620w: Global MASTER-Net observations report
- LIGO/Virgo S230619bg: Global MASTER-Net observations report
- LIGO/Virgo S230618s: Global MASTER-Net observations report
- GRB 230618A: Swift-XRT refined Analysis
- LIGO/Virgo S230616aa: Global MASTER-Net observations report
- LIGO/Virgo S230615ak: Global MASTER-Net observations report
- LIGO/Virgo S230618k: Global MASTER-Net observations report
- LIGO/Virgo S230618d: Global MASTER-Net observations report
- LIGO/Virgo S230617bc: Global MASTER-Net observations report
- LIGO/Virgo S230617aq: Global MASTER-Net observations report
- LIGO/Virgo S230617ab: Global MASTER-Net observations report
- Swift GRB 230618A: Global MASTER-Net observations report
- LIGO/Virgo S230617aj: Global MASTER-Net observations report
- GRB230618A: LCOGT Optical Observations
- GRB 230618A: Prompt enhanced Swift-XRT position
- GRB 230618A: Swift detection of a burst
- LIGO/Virgo/KAGRA S230615az: Non-Detections of GROWTH-India Candidates from GECKO Optical Observations
- LIGO/Virgo S230615be: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S230615az: GROWTH-India candidates
- GRB 230606A: LCOGT Optical Observations
- LIGO/Virgo S230608aw: Global MASTER-Net observations report
- LIGO/Virgo S230609a: Global MASTER-Net observations report
- LIGO/Virgo S230608ah: Global MASTER-Net observations report
- LIGO/Virgo S230608q: Global MASTER-Net observations report
- ZTF23aamxeqf/AT2023jxk: 1.3m DFOT Optical upper limit
- Fermi trigger No 707039690: Global MASTER-Net observations report
- ZTF and GIT Observations of the Candidate Optical Afterglow AT2023jxk
- LIGO/Virgo S230606d: Global MASTER-Net observations report
- Fermi-LAT gamma-ray observations of IceCube-230603A
- IceCube-230603A: Upper limits from a search for additional neutrino events in IceCube
- IceCube-230603A - IceCube observation of a high-energy neutrino candidate track-like event
- LIGO/Virgo S230603aa: Global MASTER-Net observations report
- LIGO/Virgo S230602ap: Global MASTER-Net observations report
- GRB 230522A: GRBAlpha and VZLUSAT-2 joint detection
- LIGO/Virgo S230529ay: Global MASTER-Net observations report
- LIGO/Virgo S230525a: Global MASTER-Net observations report
- Fermi trigger No 706610076: Global MASTER-Net observations report
- Fermi Gamma-ray Burst Monitor trigger 706536788/230523509 is not a GRB
- LIGO/Virgo S230522a: Global MASTER-Net observations report
- LIGO/Virgo S230521k: Global MASTER-Net observations report
- Fermi Gamma-ray Burst Monitor trigger 706338208/230521211 is not a GRB
- LIGO/Virgo S230520ae: Global MASTER-Net observations report
- Fermi trigger No 706331483: Global MASTER-Net observations report
- Fermi trigger No 706317104: Global MASTER-Net observations report
- GRB 230520A: CALET Gamma-Ray Burst Monitor detection
- GRB 230521A: Fermi GBM Final Real-time Localization
- LIGO/Virgo/KAGRA S230518h: ATCA follow-up of candidate counterparts
- LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
- GRB 230520A: MAXI/GSC detection
- LIGO/Virgo/Kagra S230518h: NED Galaxies in the Localization Volume
- LIGO/Virgo S230518h: Global MASTER-Net observations report
- GRB 230513A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
- GRB 230512A: Liverpool Telescope observations
- Fermi-LAT gamma-ray observations of IceCube-230511A
- GRB 230510A: OHP/T193 and OHP/T120 optical observations
- IceCube-230511A: Upper limits from a search for additional neutrino events in IceCube
- GRB 230510A: LCOGT Optical Upper Limit
- IceCube-230511A: IceCube observation of a high-energy neutrino candidate
- GRB 230511C: Fermi GBM Final Localization
- GRB 230510B: MAXI/GSC detection
- Fermi trigger No 705413051: Global MASTER-Net observations report
- Fermi Gamma-ray Burst Monitor trigger 230510133/705381054 is not a GRB
- GRB 230506C: NUTTelA-TAO / BSTI Early Optical Limits
- Fermi trigger No 704365743: Global MASTER-Net observations report
- GRB 230420A: BOOTES-5/JGT optical afterglow detection
- GRB 230307A: iTelescope optical upper limit (likely)
- GRB 230409B: OHP/T193 optical upper limit
- Fermi GRB 230409C: Global MASTER-Net observations report
- GRB 230405B: AGILE detection
- GRB 230405B: Fermi GBM Observation
- IceCube Alert 230405.56: Global MASTER-Net observations report
- GRB 230405B: Swift detection of a burst
- GRB 230405B: Fermi GBM Final Real-time Localization
- GRB 230405A: Fermi GBM Final Real-time Localization
- IceCube-230401A: Upper limits from a search for additional neutrino events in IceCube
- GRB 230328B: Multa observatory optical afterglow observation
- IceCube-Cascade 230329A: Upper limits from a search for additional neutrino events in IceCube