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"
3382 results found.
- LIGO/Virgo S190727h: No transient candidates in CALET observations
- LIGO/Virgo S190728q Global MASTER-Net observations report
- Fermi trigger No 585988241 Global MASTER-Net observations report
- GRB 190728A: Fermi GBM Final Real-time Localization
- LIGO/Virgo S190727h: No counterpart candidates in KAIT observations
- LIGO/Virgo S190720a: Thacher Observatory follow-up observations
- Fermi trigger No 585621841 Global MASTER-Net observations report
- LIGO/Virgo S190720a: No counterpart candidates in KAIT observations
- LIGO/Virgo S190718y: No counterpart candidates in CNEOST
- LIGO/Virgo S190718y: No counterpart candidates in KAIT observations
- LIGO/Virgo S190718y: Upper limits from CALET observations
- Fermi trigger No 584977168 Global MASTER-Net observations report
- Fermi trigger No 584929684 Global MASTER-Net observations report
- IPN triangulation of GRB 190706C (long/very bright)
- LIGO/Virgo S190707q: Upper limits from CALET observations
- LIGO/Virgo S190706ai: No counterpart candidates in KAIT observations
- Fermi trigger No 584007338 Global MASTER-Net observations report
- Trigger 913042: Swift triggered on noise peak
- LIGO/Virgo S190630ag: no counterpart candidate in the SVOM/GWAC observations
- LIGO/Virgo S190701ah: KMTNet Observation
- LIGO/Virgo S190701ah: No transient candidates from CALET observations
- GRB 190627A: Koshka Zeiss-1000 optical counterpart observations
- GRB 190627A: GMG observation at the second epoch
- GRB 190627A: NUTTelA-TAO optical counterpart observations
- GRB 190628A: Fermi GBM Final Real-time Localization
- Fermi trigger No 583111521 Global MASTER-Net observations report
- Swift Trigger 911102: a possible GRB
- Fermi trigger No 582856902 Global MASTER-Net observations report
- Fermi trigger No 582759998 Global MASTER-Net observations report
- Fermi trigger No 582615488 Global MASTER-Net observations report
- Fermi trigger No 582304592 Global MASTER-Net observations report
- GRB 190613B: SEDM Observations
- Fermi trigger No 582115625 Global MASTER-Net observations report
- IPN Triangulation of GRB 190611B
- Fermi trigger No 581889628 Global MASTER-Net observations report
- Fermi trigger No 581882394 Global MASTER-Net observations report
- LIGO/Virgo S190602aq: Upper limits from CALET observations
- LIGO/Virgo S190602aq: Coverage and upper limits from MAXI/GSC observations
- Fermi Fermi trigger No 581002688 Global MASTER-Net observations report
- GRB 190530A: Swift/UVOT Detection
- GRB 190530A: Swift-XRT afterglow detection
- GRB 190530A: GWAC-F30 optical detection
- GRB 190530A: OAJ optical detection
- GRB 190530A: AGILE/GRID analysis
- LIGO/Virgo S190519bj: AstroSat CZTI upper limits
- LIGO/Virgo S190521r: CNEOST follow-up observations
- Fermi GRB190525.67 Global MASTER-Net observations report
- LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC observations.
- LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC-F30 observations.
- LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC observations.
- LIGO/Virgo S190521g: No Counterparts in DDOTI/OAN Optical Observations
- S190519bj: No transient candidates from CALET observations
- LIGO/Virgo S190512at: SVOM/GWAC-F60A observations
- LIGO/Virgo S190519bj Global MASTER-Net observations report
- LIGO/Virgo S190517h: CALET Observations
- LIGO/Virgo S190518bb Global MASTER-Net observations report
- LIGO/Virgo S190517h Global MASTER-Net observations report
- LIGO/Virgo S190513bm: Swope follow-up observations
- LIGO/Virgo S190513bm : TAROT-Calern and TAROT-Chile (TCA/TCH)/GRANDMA observation report.
- LIGO/Virgo S190513bm: CALET Observations
- LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
- LIGO/Virgo S190510g: Swift-XRT observations and results
- LIGO/Virgo S190512at: CALET Observations
- LIGO/Virgo S190513bm: AGILE GRID observations
- LIGO/Virgo S190513bm: INTEGRAL prompt observation
- LIGO/Virgo S190513bm: AGILE MCAL observation
- LIGO/Virgo S190513bm Global MASTER-Net observations report
- LIGO/Virgo S190510g: Pan-STARRS and ATLAS observations and candidates
- LIGO/Virgo S190512at Global MASTER-Net observations report
- GRB 190512A: Fermi GBM observation
- LIGO/Virgo S190510g: CALET Observations
- LIGO/Virgo S190510g: MASTER OT detection inside low surface brightness galaxy
- GRB 190511A: Fermi GBM observation
- LIGO/Virgo S190510g: DESGW counterpart candidates over 80% of the GW localization area
- LIGO/Virgo S190510g: Dabancheng/HMT Follow-Up Observations
- LIGO/Virgo S190510g: SOAR/Goodman follow-up observations
- LIGO/Virgo S190510g: CNEOST Follow-Up Observations
- LIGO/Virgo S190510g: J-GEM optical/NIR follow-up observations
- LIGO/Virgo S190510g: Lick/KAIT Follow-Up Observations
- LIGO/Virgo S190510g: Lulin Optical Follow-up Observations
- LIGO/Virgo S190425z: CAHA-GRANDMA Observation of the Swift UVOT Source
- LIGO/Virgo S190426c: Archival VLASS Observations of ZTF19aassfws 14 days prior to Merger
- Fermi GRB190507.97 Global MASTER-Net observations report
- Fermi GRB190507.27 Global MASTER-Net observations report
- IceCube-190504A: MASTER optical monitoring analysis
- Fermi Trigger 578903308 / GRB 190507270 / GRB190507A: BALROG localization
- GRB 190507A: Fermi GBM Final Real-time Localization
- Fermi GRB190505.05 Global MASTER-Net observations report
- Fermi GRB190504.68 Global MASTER-Net observations report
- LIGO/Virgo S190503bf Global MASTER-Net observations report
- IceCube-190503A: Lick/KAIT Follow-Up Observations
- IPN triangulation of GRB 190504A (short)
- LIGO/Virgo S190503bf: Fermi-GBM Observations
- LIGO/Virgo S190503bf: INTEGRAL prompt observation
- LIGO/Virgo S190425z: Insight-HXMT observation and counterpart search
- Fermi GRB190501.79 Global MASTER-Net observations report
- LIGO/Virgo S190426c: PS1 historical detections and ZTF photometry of Gaia19boq AT2019egk
- LIGO/Virgo S190425z: 1.3-m optical imaging of UVOT transient field
- LIGO/Virgo S190426c: YAHPT Optical Observation
- LIGO/Virgo S190425z: KPED Follow-Up of ZTF transients