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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.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').

51 results found.

  1. LIGO/Virgo/KAGRA S250206dm: NEWFIRM NIR Follow-up of AT2025ber
  2. LIGO/Virgo/KAGRA S250206dm: GECKO Continued Observaiton with 7DT
  3. LIGO/Virgo/KAGRA S250206dm: AT 2025bbo observations with WFST
  4. LIGO/Virgo/KAGRA S250206dm: continued in SOAR galaxy targeted observations and identification of one possible transient
  5. LIGO/Virgo/KAGRA S250206dm: Kinder confirmation of a possible artefact in AT 2025bbo
  6. LIGO/VIRGO/KAGRA S250206dm: AT 2025bbo spectroscopic observations with NIRES on Keck II
  7. LIGO/Virgo/KAGRA S250206dm: Gemini-North spectroscopic observation of AT2025bbo and its host galaxy
  8. LIGO/Virgo/KAGRA S250206dm: MASTER detection AT2025bbo
  9. LIGO/Virgo/KAGRA S250206dm: Upper limits from GECAM Observations
  10. LIGO/Virgo/KAGRA S250206dm: Global MASTER-Net observations report
  11. LIGO/Virgo/KAGRA S250206dm: COLIBRÍ/DDRAGO Observations of AT2025bbo and Galaxies in the Localization Volume
  12. LIGO/Virgo/KAGRA S250206dm: Observations from WINTER
  13. LIGO/Virgo/KAGRA S250206dm & FRB 20250206A: MASTER observations and possible mother galaxy
  14. LIGO/Virgo/KAGRA S250206dm: Optical observations of candidate AT 2025bbo with Kinder
  15. LIGO/Virgo/KAGRA S250206dm: WFST follow-up observations
  16. LIGO/Virgo/KAGRA S250206dm: FRB 20250206A BOOTES-5 and 2.2m CAHA optical upper limits
  17. LIGO/Virgo/KAGRA S250206dm: further Pan-STARRS observations and one candidate AT2025bbo
  18. LIGO/Virgo/KAGRA S250206dm: GECKO Observation with 7DT and KMTNet
  19. LIGO/Virgo/KAGRA S250206dm: (Update-7) NED Galaxies in the Localization Volume
  20. LIGO/Virgo/KAGRA S250206dm: NEWFIRM NIR Observations
  21. LIGO/Virgo/KAGRA S250206dm: Updated Sky localization and EM Bright Classification
  22. LIGO/Virgo/KAGRA S250206dm: Spectroscopic Classification of AT2025bay and AT2025baz with Keck I/LRIS
  23. LIGO/Virgo/KAGRA S250206dm: Candidates from the Zwicky Transient Facility
  24. LIGO/Virgo/KAGRA S250206dm: ePESSTO+ classification of AT2025bar
  25. LIGO/Virgo/KAGRA S250206dm: COLIBRÍ/DDRAGO Observations of the DDOTI optical candidates
  26. LIGO/Virgo/KAGRA S250206dm: MMT galaxy targeted observations
  27. LIGO/Virgo/KAGRA S250206dm: FRB 20250206A & "Time Machine" Effect.
  28. CHIME/FRB source FRB 20250206A detected less than 1 minute after LIGO-Virgo-Kagra (LVK) S250206dm, however the probability of spatial coincidence is order 0.1%
  29. LIGO/Virgo/KAGRA S250206dm: GOTO counterpart search update - AT2025bar
  30. EP-WXT trigger 01709131361 / LIGO/Virgo/KAGRA S250206dm: FTW optical and NIR observations
  31. LIGO/Virgo/KAGRA S250206dm: ATLAS observations of the skymap
  32. LIGO/Virgo/KAGRA S250206dm: Pan-STARRS survey of the skymap for optical transients
  33. LIGO/Virgo/KAGRA S250206dm: DDOTI Upper Limits
  34. IGO/Virgo/KAGRA S250206dm: Virtual Telescope Project upper limit for the Neutrino IceCube Candidate
  35. LIGO/Virgo/KAGRA S250206dm:GLADEnet Completeness: Potential Host Galaxies in the 90% Credible Volume
  36. LIGO/Virgo/KAGRA S250206dm: DDOTI Upper Limit for the Neutrino IceCube Candidate
  37. LIGO/Virgo/KAGRA S250206dm: GOTO observations of optical candidates AT 2025azn and AT 2025azm
  38. LIGO/Virgo/KAGRA S250206dm: SOAR galaxy targeted observations
  39. LIGO/Virgo/KAGRA S250206dm: Pan-STARRS observations of AT2025azm and AT2025azn
  40. LIGO/Virgo/KAGRA S250206dm: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  41. LIGO/Virgo/KAGRA S250206dm: COLIBRÍ/DDRAGO Observations of the AT 2025azn Optical Candidate
  42. LIGO/Virgo/KAGRA S250206dm: SAGUARO Detection of Two Potential Optical Counterparts
  43. LIGO/Virgo/KAGRA S250206dm: Updated-6 NED Galaxies in the Localization Volume
  44. LIGO/Virgo/KAGRA S250206dm: Updated Sky localization and EM Bright Classification
  45. LIGO/Virgo/KAGRA S250206dm: Upper limits from Fermi-GBM Observations
  46. LIGO/Virgo/KAGRA S250206dm: Coverage and upper limits from MAXI/GSC observations
  47. LIGO/Virgo/KAGRA S250206dm: Updated Sky localization and EM Bright Classification
  48. LIGO/Virgo/KAGRA S250206dm: Updated NED Galaxies in the Localization Volume
  49. LIGO/Virgo/KAGRA S250206dm: Two counterpart neutrino candidates from IceCube neutrino searches
  50. LIGO/Virgo/KAGRA S250206dm: Identification of a GW compact binary merger candidate
  51. LIGO/Virgo/KAGRA S250206dm: NED Galaxies in the Localization Volume

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