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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').
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"

64 results found.

  1. GRB 260421B: SVOM/COLIBRÍ (FM-GFT) optical detection of a candidate counterpart
  2. Fermi trigger No 792135758: Global MASTER-Net observations report
  3. SVOM GRB260121.06: Global MASTER-Net observations report
  4. GRB 250620B: Fermi GBM Observation
  5. Swift GRB 250520A: Global MASTER-Net observations report
  6. IceCube-241113A - IceCube observation of a high-energy neutrino candidate track-like event
  7. Fermi GRB 241104A: Global MASTER-Net observations report
  8. LIGO/Virgo/KAGRA S240422ed: Zwicky Transient Facility contuinued observations of S240422ed and candidate analysis
  9. Swift GRB240123.46: Global MASTER-Net observations report
  10. GRB 230808A: Fermi GBM Detection
  11. GRB 230803A: AstroSat CZTI detection
  12. Fermi GRB 230723A: Global MASTER-Net observations report
  13. Fermi GRB 220211B: Global MASTER-Net observations report
  14. Fermi GRB 210621A: Global MASTER-Net observations report
  15. Fermi trigger No 645047470: Global MASTER-Net observations report
  16. Swift GRB 210610B: Global MASTER-Net observations report
  17. Fermi GRB 210503A: Global MASTER-Net observations report
  18. IceCube-201021A: No neutrino counterpart candidates in ANTARES search
  19. IceCube-201014A: No neutrino counterpart candidates in ANTARES search
  20. IceCube-200916A: No neutrino counterpart candidates in ANTARES search
  21. HAWC-200907A: No Neutrino Counterpart detected with ANTARES
  22. Fermi GRB 200605A: Global MASTER-Net observations report
  23. GRB 200524A: AstroSat CZTI detection
  24. Fermi trigger No 601841483: Global MASTER-Net observations report
  25. GRB 200125A: Swift-BAT refined analysis
  26. Swift GRB191226.02: Global MASTER-Net observations report
  27. GRB 191031D: AGILE/MCAL observations
  28. Swift GRB190718.2 Global MASTER-Net observations report
  29. Fermi trigger No 581645543 Global MASTER-Net observations report
  30. LIGO/Virgo S190426c: Discovery Channel Telescope Follow-Up of ZTF19aassfws
  31. LIGO/Virgo S190412m: Palomar Gattini-IR Wide-field Infrared Follow-up
  32. GRB 181023A: Swift/UVOT Upper Limits
  33. GRB 180614A: Swift/UVOT Upper Limits
  34. GRB 180311A: Swift/UVOT Upper Limits
  35. GRB 170711A: Swift/UVOT Upper Limits
  36. GRB 160425A: Swift/UVOT Detection
  37. GRB 160313A: Swift/UVOT Upper Limits
  38. LIGO/Virgo G211117: Identification of a GW CBC Candidate
  39. GRB 151031A: Swift/UVOT Detection
  40. GRB 151022A: Swift/UVOT Upper Limits
  41. Konus-Wind observation of GRB 150403A
  42. Swift-BAT refined analysis of magnetar 4U 0142+61 (Trigger 632888)
  43. Swift trigger 601928 is V490 Cep: BAT+XRT refined analysis.
  44. Konus-Wind observation of GRB 140508A
  45. GRB 140103A: MASTER-Net early OT detection
  46. GRB 131229A: Swift-BAT refined analysis
  47. GRB 130929A: Swift/UVOT Upper Limits
  48. GRB 130615A: Swift/UVOT Upper Limits
  49. GRB130427A: Swift/UVOT followup observations of an Optical Afterglow
  50. GRB 120728A: Swift/UVOT Upper Limits
  51. Swift detection of Ginga 0834-430
  52. Konus-Wind observation of GRB 120328B
  53. GRB 111123A: Swift/UVOT Upper Limits
  54. GRB 110402A: Swift/UVOT detection of afterglow candidate
  55. GRB 100413A: Swift-XRT Refined Analysis
  56. GRB 080723A: Swift/UVOT Upper Limits
  57. Swift/UVOT observations of GRB080409
  58. GRB 071112C: Optical and NIR data observed with KANATA
  59. GRB 050730: XRT refined analysis
  60. GRB050712: Swift UVOT Observation of Afterglow Emission
  61. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  62. IPN BURST POSITION
  63. GRB 991105: BATSE Observations
  64. BeppoSAX NFI observations of GRB 980703

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