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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"

6829 results found.

  1. GRB 191031D: Fermi GBM detection
  2. GRB 191031A: Fermi GBM detection
  3. GRB 191029A: CORRECTED Swift-XRT refined analysis
  4. GRB 191029A: Swift/UVOT Upper Limits
  5. GRB 191029A: Swift-XRT refined Analysis
  6. Swift Trigger 931384: possible GRB 191025A
  7. GRB 191024A: Swift-XRT refined Analysis
  8. GRB191024A: MASTER optical observation
  9. GRB 191019A: Nanshan-0.6m optical observations
  10. GRB 191019A: Swift-XRT updated analysis
  11. GRB 191019A: Swift-XRT refined Analysis
  12. Alert from the HAWC Burst Monitor HAWC-191019A
  13. GRB 191017B: Swift-XRT refined Analysis
  14. GRB 191016A: Swift-XRT afterglow detection
  15. GRB 191016A: Swift/UVOT Detection
  16. GRB 191011A: Fermi GBM observation
  17. GRB 191011A: Swift-XRT refined Analysis
  18. LIGO/Virgo S190930t: Continued Swift observations of AT2019sbk
  19. Fermi/GBM observation of a bright burst from magnetar SGR 1935+2154
  20. LIGO/Virgo S190930t: Swift XRT observations, no secure afterglow found
  21. LIGO/Virgo S190930t: SALT optical spectroscopy of Swift J221951-484240
  22. GRB 191004B: Swift-XRT refined Analysis
  23. GRB 191004A: Swift-XRT refined Analysis
  24. GRB 191001A: Swift-XRT observations
  25. LIGO/Virgo S190930t: Continued Swift/UVOT observations of Swift J221951-484240
  26. GRB 191001A: Fermi GBM observation
  27. IceCube-191001A: HAWC follow-up
  28. Fermi-LAT Gamma-ray Observations of IceCube-191001A
  29. LIGO/Virgo S190930t: HCT observations of ZTF19acbpsuf
  30. LIGO/Virgo S190930t: Lulin Follow-up Observations of AT2019rpn and AT2019rpj
  31. IceCube-191001A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  32. LIGO/Virgo S190923y: optical spectrum of MASTER detected transient
  33. LIGO/Virgo S190930t: Transient found in Swift/UVOT counterpart search
  34. LIGO/Virgo S190930t: No counterpart candidates in Fermi-LAT observations
  35. LIGO/Virgo S190930s: No counterpart candidates in Fermi-LAT observations
  36. LIGO/Virgo S190930t: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  37. LIGO/Virgo S190930s: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  38. GRB 190926A: Swift-XRT refined Analysis
  39. LIGO/Virgo S190924h: No counterpart candidates in Fermi-LAT observations
  40. LIGO/Virgo S190924h: no counterpart candidates in AGILE-GRID observations
  41. Fermi-LAT Gamma-ray Observations of IceCube-190922B
  42. LIGO/Virgo S190924h: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  43. LIGO/Virgo S190923y: No counterpart candidates in Fermi-LAT observations
  44. Fermi-LAT Gamma-ray Observations of IceCube-190922A
  45. IceCube-190922B - HAWC follow-up
  46. LIGO/Virgo S190923y: INTEGRAL IBIS coded-masked imaging observations of part of the localization area and further all-sky upper limits
  47. LIGO/Virgo S190923y: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  48. IceCube-190922A - HAWC follow-up
  49. IceCube-190922A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  50. GRB 190919B: Swift-XRT observations
  51. GRB 190919B: GROND detection of the NIR afterglow
  52. HAWC-190916A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  53. Alert from the HAWC Burst Monitor HAWC-190917A
  54. LIGO/Virgo S190915ak: No counterpart candidates in Fermi-LAT observations
  55. LIGO/Virgo S190915ak: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  56. LIGO/Virgo S190910h: No counterpart candidates in Fermi-LAT observations
  57. LIGO/Virgo S190910d: No counterpart candidates in Fermi-LAT observations
  58. LIGO/Virgo S190910h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  59. LIGO/Virgo S190910d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  60. GRB 190823A: Swift-XRT afterglow detection
  61. GRB 190903A: Fermi GBM detection
  62. Chandra observations of GW170817 ~740-743 days since merger
  63. LIGO/Virgo S190901ap: No counterpart candidates in Fermi-LAT observations
  64. LIGO/Virgo S190901ap: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  65. GRB 190829A: TNG imaging of the NIR afterglow
  66. GRB 190829A: Fermi GBM detection
  67. GRB 190829A: Fermi-LAT Upper Limits
  68. GRB 190829A: GROND detection of the Optical/NIR Afterglow
  69. GRB 190829A: Swift-XRT refined Analysis
  70. GRB 190828B: Swift-XRT refined Analysis
  71. GRB 190828A: Swift-XRT observations
  72. LIGO/Virgo S190828l: No counterpart candidates in Fermi-LAT observations
  73. GRB 190828B: Fermi GBM observation
  74. LIGO/Virgo S190828j: No counterpart candidates in Fermi-LAT observations
  75. LIGO/Virgo S190814bv: no variation of DESGW candidates AT 2019onj and AT 2019okr from ENGRAVE VLT/HAWK-I observations, and archival detection
  76. LIGO/Virgo S190828l: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  77. LIGO/Virgo S190828j: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  78. LIGO/Virgo S190814bv: SALT optical spectrum of candidate DG19aqbkc
  79. LIGO/Virgo S190814bv: LCO Photometry of DG19wxnjc/AT2019npv
  80. GRB 190823A: Swift-XRT observations
  81. GRB 190816A: Swift-XRT afterglow detection
  82. GRB 190824A: Swift-XRT refined Analysis
  83. GRB 190824A: Fermi GBM observation
  84. LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv
  85. LIGO/Virgo S190814bv: ENGRAVE VLT/HAWK-I observations and archival detection of the CFHT candidate
  86. GRB 190821A: Swift-XRT refined Analysis
  87. GRB 190821A: Fermi GBM observation
  88. Fermi GBM-190816: No counterpart candidates in Fermi-LAT observations
  89. Fermi-LAT Gamma-ray Observations of IceCube-190819A
  90. IceCube-190819A - HAWC follow-up
  91. Fermi GBM-190816: Location-dependent upper limits from INTEGRAL/SPI-ACS prompt observation
  92. IceCube-190819A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  93. LIGO/Virgo S190814bv: No strong counterpart candidates in Swift/XRT observations
  94. GRB 190816A: Swift-XRT observations
  95. LIGO/Virgo S190814bv: Fermi-LAT search for a high-energy gamma-ray counterpart
  96. LIGO/Virgo S190814bv: GRAWITA TNG infrared imaging of desgw-190814e, DG19sevhc and selected galaxies
  97. LIGO/Virgo S190814bv: Konus-Wind observations
  98. LIGO/Virgo S190814bv: GRAWITA TNG infrared imaging of selected galaxies
  99. LIGO/Virgo S190814bv: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  100. HAWC-190806A: upper limits from INTEGRAL SPI-ACS and IBIS prompt observation

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