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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

27334 results found.

  1. GRB 191221B: MASTER VWFC OT yearly detection
  2. LIGO/Virgo S191222n: not observable by Fermi-GBM
  3. LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
  4. LIGO/Virgo S191222n: No counterpart candidates in HAWC observations
  5. LIGO/Virgo S191222n: Global MASTER-Net observations report
  6. Baksan Neutrino Observatory Alert 191222.09: Global MASTER-Net observations report
  7. GRB 191221B: Swift/UVOT redshift
  8. Swift GRB 191221B: Global MASTER-Net observations report
  9. GRB 191220A: Swift-BAT refined analysis
  10. GRB 191221B: Swift detection of a burst and a very bright optical candidate
  11. Fermi trigger No 598648473: Global MASTER-Net observations report
  12. GRB 191221A: Fermi GBM Final Real-time Localization
  13. GRB 191220A: Swift/UVOT Upper Limits
  14. GRB 191220A: Swift-XRT refined Analysis
  15. Fermi trigger No 598543714: Global MASTER-Net observations report
  16. GRB 191220A: SAO RAS possible OT detection
  17. GRB 191220A: Swift detection of a burst
  18. Swift GRB191220.56: Global MASTER-Net observations report
  19. LIGO/Virgo S191220af: Retraction of GW compact binary merger candidate
  20. LIGO/Virgo S191220af: Global MASTER-Net observations report
  21. LIGO/Virgo S191216ap: AstroSat CZTI upper limits
  22. Konus-Wind observation of GRB 191218A
  23. LIGO/Virgo S191213g: Swift UVOT/XRT observations of Pan-STARRS1 candidate: PS19hgw
  24. LIGO/Virgo S191216ap, Swift XRT observations: 16 X-ray sources in the HAWC error region search
  25. GRB 191218A: Swift-BAT refined analysis
  26. LIGO/Virgo S191213g: No counterpart candidate in the NOWT observations
  27. LIGO/Virgo S191213g: Pan-STARRS1 discovery of a potential optical counterpart
  28. Konus-Wind observation of GRB 191213A (ulong)
  29. LIGO/Virgo S191216ap: GRAWITA Loiano observations of HAWC error region
  30. LIGO/Virgo S191216ap: No transient candidates in CALET observations
  31. GRB 191218A: Swift detection of a burst
  32. LIGO/Virgo S191216ap: Nanshan follow-up observations
  33. LIGO/Virgo S191216ap: galaxies consistent with GW + Neutrino + HAWC position
  34. LIGO/Virgo S191216ap and IceCube neutrino: Swift XRT sources
  35. LIGO/Virgo S191216ap: IceCube event: MASTER OF detection in GW and Neutrino error field
  36. LIGO/Virgo S191216ap: No significant counterpart candidates in SAGUARO observations
  37. LIGO/Virgo S191216ap: HAWC gamma-ray sub-threshold event coincident with LIGO/Virgo and IceCube localizations
  38. LIGO/Virgo S191213g: Swift UVOT/XRT observations of three ZTF sources
  39. LIGO/Virgo S191215w : No significant candidates in TAROT - FRAM - GRANDMA observations.
  40. LIGO/Virgo G191216ap: No counterpart candidates in Fermi-LAT observations
  41. LIGO/Virgo S191216ap: no counterpart candidates in the Swift/BAT observations
  42. LIGO/Virgo S191215w: No transient candidates in CALET observations
  43. LIGO/Virgo S191216ap: No Candidates from the Zwicky Transient Facility
  44. LIGO/Virgo S191216ap: Coverage and upper limits from MAXI/GSC observations
  45. LIGO/Virgo S191216ap: Upper limits from Fermi-GBM Observations
  46. LIGO/Virgo S191216ap: 1 counterpart neutrino candidate from IceCube neutrino searches
  47. LIGO/Virgo S191216ap: Global MASTER-Net observations report
  48. LIGO/Virgo S191216ap: No counterpart candidates in HAWC observations
  49. LIGO/Virgo S191215w: no counterpart candidates in the Swift/BAT observations
  50. LIGO/Virgo S191215w: No counterpart candidates in Fermi-LAT observations
  51. LIGO/Virgo S191215w: AstroSat CZTI upper limits
  52. LIGO/Virgo S191215w: Upper limits from Fermi-GBM Observations
  53. LIGO/Virgo S191215w: No counterpart candidates in HAWC observations
  54. LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC observations
  55. LIGO/Virgo S191215w: Global MASTER-Net observations report
  56. IceCube Alert 191215.47: Global MASTER-Net observations report
  57. LIGO/Virgo S191213g: Upper limits from Insight-HXMT/HE observations
  58. LIGO/Virgo S191213g: Pan-STARRS1 previous detections of ZTF19acykzsk
  59. LIGO/Virgo S191213g: AstroSat CZTI upper limits
  60. LIGO/Virgo S191213g: Candidates from the Zwicky Transient Facility
  61. LIGO/Virgo S191213g: No neutrino candidates at Pierre Auger Observatory
  62. GRB 191213A: BOOTES-5/JGT optical limit
  63. LIGO/Virgo S191213g: No transient candidates in CALET observations
  64. GRB 191213A: Swift-BAT refined analysis
  65. LIGO/Virgo S191205ah: Candidates from the Zwicky Transient Facility Public Survey
  66. Fermi trigger No 597955752: Global MASTER-Net observations report
  67. GRB 191213B: Fermi GBM Final Real-time Localization
  68. LIGO/Virgo S191213ai: Retraction of GW compact binary merger candidate
  69. LIGO/Virgo S191213g: No counterpart candidates in Fermi-LAT observations
  70. LIGO/Virgo S191213ai: Global MASTER-Net observations report
  71. LIGO/Virgo S191213g: no counterpart candidates in the Swift/BAT observations
  72. LIGO/Virgo S191213g: Upper limits from Fermi-GBM Observations
  73. Fermi trigger No 597909938: Global MASTER-Net observations report
  74. LIGO/Virgo S191213g: Coverage and upper limits from MAXI/GSC observations
  75. LIGO/Virgo S191213g: Global MASTER-Net observations report
  76. GRB 191213A: Swift detection of a burst
  77. LIGO/Virgo S191212q: Retraction of GW compact binary merger candidate
  78. LIGO/Virgo S191212q: Global MASTER-Net observations report
  79. Baksan Neutrino Observatory Alert 191211.1: Global MASTER-Net observations report
  80. Possible HAWC-detected GRB 191210A: Fermi-LAT Upper Limits
  81. Fermi GBM trigger 597737032/191211253 is not a GRB
  82. Fermi trigger No 597737032: Global MASTER-Net observations report
  83. LIGO/Virgo S191205ah: no counterpart candidate in SVOM/GWAC observations
  84. GRB 191207A: Possible GRB detected in Fermi-LAT blind search
  85. LIGO/Virgo S191205ah : No significant candidates in FRAM - TAROT – GRANDMA observations
  86. LIGO/Virgo S191205ah: Not observable by CALET
  87. LIGO/Virgo S191205ah: AstroSat CZTI upper limits
  88. IceCube-191204A : Upper limits from Insight-HXMT/HE observations
  89. LIGO/Virgo S191205ah: Upper limits from Insight-HXMT/HE observations
  90. LIGO/Virgo S191204r: Upper limits from Insight-HXMT/HE observations
  91. GRB 191203A: Insight-HXMT/HE detection
  92. GRB 191202A: Insight-HXMT/HE detection
  93. LIGO/Virgo S191205ah: No neutrino candidates at Pierre Auger Observatory
  94. LIGO/Virgo S191205ah: GMG detection of SAGUARO transient
  95. LIGO/Virgo S191205ah: no counterpart candidates in the Swift/BAT observations
  96. LIGO/Virgo S191205ah: No counterpart candidates in Fermi-LAT observations
  97. LIGO/Virgo S191129u : No significant candidates in FRAM-TAROT-GRANDMA observations.
  98. LIGO/Virgo S191204r: No significant candidates in FRAM-TAROT-GRANDMA observations.
  99. LIGO/Virgo S191205ah: SAGUARO observations and identification of an optical candidate
  100. LIGO/Virgo S191205ah: Upper limits from Fermi-GBM Observations

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