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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"

3559 results found.

  1. Fermi trigger No 697098930: Global MASTER-Net observations report
  2. ZTF23aabmzlp/AT2023azs: Lulin 1m LOT optical observations
  3. ZTF23aaarlti/AT2023avj: Assy continued optical observations
  4. ZTF23aabmzlp/AT2023azs: 1.3m DFOT optical observations
  5. GRB 230128A: AstroSat CZTI detection
  6. ZTF23aaarlti/AT2023avj: VLA radio detection
  7. GRB 230128A: Fermi GBM Final Real-time Localization
  8. ZTF23aabmzlp/AT2023azs: Zwicky Transient Facility discovery of a fast optical transient
  9. Fermi GRB 230124A: Global MASTER-Net observations report
  10. Fermi GRB 230118A: Global MASTER-Net observations report
  11. Subject: IceCube-Cascade 221229A: Upper limits from a search for additional neutrino events in IceCube
  12. IceCube-221229A: Upper limits from a search for additional neutrino events in IceCube
  13. GRB 221228A: Fermi GBM Final Real-time Localization
  14. IceCube Alert 221223.32: Global MASTER-Net observations report
  15. GRB 221216A: Detection by VZLUSAT-2
  16. Fermi trigger No 692713692: Global MASTER-Net observations report
  17. Fermi Gamma-ray Burst Monitor triggers 692721536/221214610 and 692713692/221214520 are not GRBs
  18. Fermi GRB 221211A: Global MASTER-Net observations report
  19. IceCube Alert 221210.36: Global MASTER-Net observations report
  20. GRB 221202A: MeerLICHT upper limits
  21. Swift GRB 221201A: Global MASTER-Net observations report
  22. Alert from the HAWC Burst Monitor HAWC-221128A
  23. GRB 221120A: Detection by VZLUSAT-2
  24. Alert from the HAWC Burst Monitor HAWC-221123A
  25. GRB 221120A: AKO Telescope Upper Limits
  26. GRB 221120A: GIT upper limits on optical afterglow
  27. GRB 221120A: Swift detection of a likely short burst
  28. LAT GRB221119.63: Global MASTER-Net observations report
  29. GRB 221115A: Swift/BAT-GUANO detection
  30. GRB 221110A: GRANDMA observations
  31. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 November 9
  32. GRB 221110A: COATLI Second-Epoch Upper Limits
  33. GRB 221110A: GMG upper limit
  34. GRB 221110A: Swift detection of a burst with an optical counterpart
  35. GRB 221028A: Detection by VZLUSAT-2
  36. GRB 221028A: 1.3m DFOT Optical upper limit
  37. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  38. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  39. GRB 221029A: Detection by GRBAlpha
  40. GRB 221028A: CrAO/ZTSh optical upper limit
  41. GRB 221028A: AGILE detection
  42. GRB 221028A: MITSuME Okayama optical upper limits
  43. GRB 221028A: LCOGT Optical Upper Limits
  44. GRB 221027B: COATLI Upper Limits
  45. Swift GRB 221028A: Global MASTER-Net observations report
  46. GRB 221028A: BOOTES-4/MET optical upper limit
  47. GRB 221027B: FRAM-ORM and Ondrejov SBT optical limits
  48. Swift GRB 221027B: Global MASTER-Net observations report
  49. IPN triangulation of GRB 221022C (short)
  50. GRB 221023A: AGILE/GRID analysis
  51. IPN triangulation of GRB 221022B (long)
  52. GRB 221024A: Swift detection of a burst
  53. Fermi GBM trigger 687320613 / 221013100 (GRB 221013B) is not a GRB
  54. GRB 221013B: Swift/BAT-GUANO detection
  55. SGR 1935+2154: Bursting activity detected by VZLUSAT-2
  56. IPN triangulation of GRB 221017A (long)
  57. MAXI GRB221017.24: Global MASTER-Net observations report
  58. MAXI GRB 221006A: Redshifts of the possible host galaxies
  59. GRB 221013B: Fermi GBM Final Real-time Localization
  60. Integral GRB221012.98: Global MASTER-Net observations report
  61. Afterglow limits of GRB 221006A from OHP
  62. Fermi trigger No 687205006: Global MASTER-Net observations report
  63. GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
  64. INTEGRAL detection of a burst from SGR J1935+2154
  65. Konus-Wind detection of GRB 221009A
  66. GRB221009A/Swift J1913.1+1946: ATA follow-up observations
  67. GRB 221006A: Swift-XRT observations
  68. GRB 220921A: ATCA detection of radio counterpart
  69. Fermi trigger No 686403226: Global MASTER-Net observations report
  70. Fermi trigger No 686350260: Global MASTER-Net observations report
  71. Fermi-LAT gamma-ray observations of IceCube-220928A
  72. IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
  73. IceCube-220928A - IceCube observation of a high-energy neutrino candidate track-like event
  74. IPN triangulation of GRB 220927A (long)
  75. Fermi GRB 220925A: Global MASTER-Net observations report
  76. Fermi trigger No 685748699: Global MASTER-Net observations report
  77. LAT GRB220921.46: Global MASTER-Net observations report
  78. Fermi trigger No 685452089: Global MASTER-Net observations report
  79. Fermi trigger No 684716840: Global MASTER-Net observations report
  80. Fermi GRB 220912A: Global MASTER-Net observations report
  81. IPN triangulation of GRB 220905A
  82. IceCube Alert 220907.28: Global MASTER-Net observations report
  83. GRB 220905A: BALROG localization (Fermi Trigger 684070128 / GRB 220905478)
  84. GRB 220905A: Fermi GBM Final Real-time Localization
  85. Fermi trigger No 683646997: Global MASTER-Net observations report
  86. Fermi trigger No 683537972: Global MASTER-Net observations report
  87. Fermi trigger No 683202084: Global MASTER-Net observations report
  88. Fermi trigger No 683183601: Global MASTER-Net observations report
  89. GRB 220823A: Fermi GBM detection
  90. Fermi trigger No 682918137: Global MASTER-Net observations report
  91. GRB 220823A: Swift/BAT-GUANO detection of a short burst
  92. IceCube Alert 220822.85: Global MASTER-Net observations report
  93. Fermi GRB 220810A: Global MASTER-Net observations report
  94. Fermi trigger No 681212354: Global MASTER-Net observations report
  95. Fermi trigger No 680782656: Global MASTER-Net observations report
  96. Fermi GRB 220728A: Global MASTER-Net observations report
  97. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220728A
  98. GRB 220728A: Fermi GBM Final Real-time Localization
  99. Fermi GRB 220724A: Global MASTER-Net observations report
  100. GRB 220715B: Fermi GBM detection

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