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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"

6803 results found.

  1. GRB 200107B: Fermi GBM observation
  2. Fermi-LAT Gamma-ray Observations of IceCube-200107A
  3. IceCube-200107A: No significant detection in HAWC
  4. IceCube-200107A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  5. LIGO/Virgo 200105ae: No counterpart candidates in Fermi-LAT observations
  6. LIGO/Virgo S200105ae: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  7. Fermi-LAT Gamma-ray Observations of IceCube-191231A
  8. IceCube-191231A: No significant detection in HAWC
  9. GRB 200101A: Fermi GBM detection
  10. IceCube-191231A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  11. GRB 191228A: Swift-XRT refined Analysis
  12. GRB 191227A: Fermi GBM detection
  13. GRB 191227A: Marginal detection by Fermi-LAT
  14. GRB 191221B: iTelescope T17 detection
  15. GRB 191221B: ALMA detection
  16. GRB 191221B: Swift-XRT refined Analysis
  17. LIGO/Virgo S191222n: No counterpart candidates in Fermi-LAT observations
  18. GRB 191220A: Swift-XRT refined Analysis
  19. GRB 191220A: SAO RAS possible OT detection
  20. LIGO/Virgo S191213g: Lulin Follow-up Observations of AT2019wxt
  21. LIGO/Virgo S191213g: Swift UVOT/XRT observations of Pan-STARRS1 candidate: PS19hgw
  22. LIGO/Virgo S191216ap: No candidates found in J-GEM follow-up observations of HAWC error region
  23. LIGO/Virgo S191213g: No candidates found in J-GEM follow-up observations
  24. LIGO/Virgo S191216ap and IceCube neutrino: Swift XRT sources
  25. LIGO/Virgo S191213g: Swift UVOT/XRT observations of three ZTF sources
  26. LIGO/Virgo S191215w : No significant candidates in TAROT - FRAM - GRANDMA observations.
  27. LIGO/Virgo G191216ap: No counterpart candidates in Fermi-LAT observations
  28. Fermi-LAT Gamma-ray Observations of IceCube-191215A
  29. LIGO/Virgo S191216ap: Identification of a GW compact binary merger candidate
  30. LIGO/Virgo S191215w: No counterpart candidates in Fermi-LAT observations
  31. LIGO/Virgo S191215w: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  32. IceCube-191215A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  33. LIGO/Virgo S191213g: Lulin Follow-up Observations of ZTF19acykzsk/AT2019wqj
  34. LIGO/Virgo S191213g: No counterpart candidates in Fermi-LAT observations
  35. LIGO/Virgo S191213g: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  36. Possible HAWC-detected GRB 191210A: Fermi-LAT Upper Limits
  37. Possible HAWC-detected GRB 191210A: Swift-XRT observations
  38. GRB 191207A: Possible GRB detected in Fermi-LAT blind search
  39. IceCube-191204A: No significant detection in HAWC
  40. Fermi-LAT Gamma-ray Observations of IceCube-191204A
  41. LIGO/Virgo S191205ah: No counterpart candidates in Fermi-LAT observations
  42. LIGO/Virgo S191204r: No counterpart candidates in Fermi-LAT observations
  43. LIGO/Virgo S191205ah: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  44. GRB 191130A: Swift-XRT observations
  45. IceCube-191204A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  46. LIGO/Virgo S191204r: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  47. GRB 191202A: Fermi-LAT detection
  48. GRB 191202A: Fermi GBM observation
  49. LIGO/Virgo S191129u: No counterpart candidates in Fermi-LAT observations
  50. LIGO/Virgo S191129u: no INTEGRAL data available
  51. IceCube-191122A: No significant detection in HAWC
  52. Fermi-LAT Gamma-ray Observations of IceCube-191122A
  53. GRB 191123A: Swift-XRT refined Analysis
  54. GRB 191122A: Swift-XRT refined Analysis
  55. IceCube-191119A: No significant detection in HAWC
  56. Fermi-LAT Gamma-ray Observations of IceCube-191119A
  57. IceCube-191119A - No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  58. LIGO/Virgo S191110af: Upper limits from Konus-Wind observations
  59. LIGO/Virgo S191110af: Swift XRT observations, no secure afterglow found
  60. LIGO/Virgo S191110af: No counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  61. LIGO/Virgo S191110af: No counterpart candidates in Fermi-LAT observations
  62. LIGO/Virgo S191110af: No counterpart candidates in INTEGRAL SPI-ACS, prompt observation
  63. LIGO/Virgo S191109d: No counterpart candidates in Fermi-LAT observations
  64. LIGO/Virgo S191109d: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  65. ZTF19abvizsw: Upper limits from Konus-Wind observations
  66. LIGO/Virgo S191105e: No counterpart candidates in Fermi-LAT observations
  67. GRB 191106A: Swift-XRT refined Analysis
  68. LIGO/Virgo S191105e: No counterpart candidates in INTEGRAL SPI-ACS and,IBIS prompt observation
  69. GRB 191101A: Swift/UVOT Upper Limits
  70. GRB 191101A: iTelescope optical limit
  71. GRB 191101A: Swift-XRT refined Analysis
  72. GRB 191031C: Swift-XRT refined Analysis
  73. GRB 191031D: Swift-XRT refined Analysis
  74. GRB 191031C: Fermi GBM detection
  75. GRB 191031D: Fermi GBM detection
  76. GRB 191031A: Fermi GBM detection
  77. GRB 191029A: CORRECTED Swift-XRT refined analysis
  78. GRB 191029A: Swift/UVOT Upper Limits
  79. GRB 191029A: Swift-XRT refined Analysis
  80. Swift Trigger 931384: possible GRB 191025A
  81. GRB 191024A: Swift-XRT refined Analysis
  82. GRB191024A: MASTER optical observation
  83. GRB 191019A: Nanshan-0.6m optical observations
  84. GRB 191019A: Swift-XRT updated analysis
  85. GRB 191019A: Swift-XRT refined Analysis
  86. Alert from the HAWC Burst Monitor HAWC-191019A
  87. GRB 191017B: Swift-XRT refined Analysis
  88. GRB 191016A: Swift-XRT afterglow detection
  89. GRB 191016A: Swift/UVOT Detection
  90. GRB 191011A: Fermi GBM observation
  91. GRB 191011A: Swift-XRT refined Analysis
  92. LIGO/Virgo S190930t: Continued Swift observations of AT2019sbk
  93. Fermi/GBM observation of a bright burst from magnetar SGR 1935+2154
  94. LIGO/Virgo S190930t: Swift XRT observations, no secure afterglow found
  95. LIGO/Virgo S190930t: SALT optical spectroscopy of Swift J221951-484240
  96. GRB 191004B: Swift-XRT refined Analysis
  97. GRB 191004A: Swift-XRT refined Analysis
  98. GRB 191001A: Swift-XRT observations
  99. LIGO/Virgo S190930t: Continued Swift/UVOT observations of Swift J221951-484240
  100. GRB 191001A: Fermi GBM observation

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