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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

6829 results found.

  1. LIGO/Virgo S191215w: Upper limits from Konus-Wind observations
  2. IceCube 200117A: No significant detection in HAWC
  3. LIGO/Virgo S191213g: Upper limits from Konus-Wind observations
  4. LIGO/Virgo S191205ah: Upper limits from Konus-Wind observations
  5. LIGO/Virgo S191204r: Upper limits from Konus-Wind observations
  6. LIGO/Virgo S191129u: Upper limits from Konus-Wind observations
  7. Fermi-LAT Gamma-ray Observations of IceCube-200117A
  8. LIGO/Virgo S200115j: LCO upper limits for ZTF20aafqvyc/AT2020yq from the McDonald Observatory 1-m telescope
  9. LIGO/Virgo S200115j: NIR upper limits for ZTF20aafqvyc/AT2020yq from the Palomar 200-inch telescope
  10. IceCube-200117A: no counterpart candidates in INTEGRAL SPI-ACS and,IBIS prompt observation
  11. LIGO/Virgo S200114f: No transients found in J-GEM observations of nearby galaxies
  12. LIGO/Virgo S200115j: Swift-XRT sources
  13. LIGO/Virgo S200114f: Swift-XRT sources and observations
  14. LIGO/Virgo S200115j: No counterpart candidates in Fermi-LAT observations
  15. GRB 200115A: Nanshan-0.6m optical upper limit
  16. GRB 200115A: Swift detection of a burst
  17. LIGO/Virgo S200114f: No counterpart candidates in Fermi-LAT observations
  18. LIGO/Virgo S200114f: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  19. Fermi-LAT Gamma-ray Observations of IceCube-200109A and detection of a possible new gamma-ray source, Fermi J1055.8+1034
  20. LIGO/Virgo 200112r: No counterpart candidates in Fermi-LAT observations
  21. IceCube 200109A: No significant detection in HAWC
  22. Fermi-LAT ANTARES coincidence: No significant detection in HAWC
  23. GRB 200109A: Fermi GBM observation
  24. GRB 200107B: Swift-XRT refined Analysis
  25. Fermi-LAT ANTARES coincidence: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  26. GRB 200109A: Swift-XRT refined Analysis
  27. GRB 200107B: Fermi GBM observation
  28. Fermi-LAT Gamma-ray Observations of IceCube-200107A
  29. IceCube-200107A: No significant detection in HAWC
  30. IceCube-200107A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  31. LIGO/Virgo 200105ae: No counterpart candidates in Fermi-LAT observations
  32. LIGO/Virgo S200105ae: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  33. Fermi-LAT Gamma-ray Observations of IceCube-191231A
  34. IceCube-191231A: No significant detection in HAWC
  35. GRB 200101A: Fermi GBM detection
  36. IceCube-191231A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  37. GRB 191228A: Swift-XRT refined Analysis
  38. GRB 191227A: Fermi GBM detection
  39. GRB 191227A: Marginal detection by Fermi-LAT
  40. GRB 191221B: iTelescope T17 detection
  41. GRB 191221B: ALMA detection
  42. GRB 191221B: Swift-XRT refined Analysis
  43. LIGO/Virgo S191222n: No counterpart candidates in Fermi-LAT observations
  44. GRB 191220A: Swift-XRT refined Analysis
  45. GRB 191220A: SAO RAS possible OT detection
  46. LIGO/Virgo S191213g: Lulin Follow-up Observations of AT2019wxt
  47. LIGO/Virgo S191213g: Swift UVOT/XRT observations of Pan-STARRS1 candidate: PS19hgw
  48. LIGO/Virgo S191216ap: No candidates found in J-GEM follow-up observations of HAWC error region
  49. LIGO/Virgo S191213g: No candidates found in J-GEM follow-up observations
  50. LIGO/Virgo S191216ap and IceCube neutrino: Swift XRT sources
  51. LIGO/Virgo S191213g: Swift UVOT/XRT observations of three ZTF sources
  52. LIGO/Virgo S191215w : No significant candidates in TAROT - FRAM - GRANDMA observations.
  53. LIGO/Virgo G191216ap: No counterpart candidates in Fermi-LAT observations
  54. Fermi-LAT Gamma-ray Observations of IceCube-191215A
  55. LIGO/Virgo S191216ap: Identification of a GW compact binary merger candidate
  56. LIGO/Virgo S191215w: No counterpart candidates in Fermi-LAT observations
  57. LIGO/Virgo S191215w: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  58. IceCube-191215A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  59. LIGO/Virgo S191213g: Lulin Follow-up Observations of ZTF19acykzsk/AT2019wqj
  60. LIGO/Virgo S191213g: No counterpart candidates in Fermi-LAT observations
  61. LIGO/Virgo S191213g: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  62. Possible HAWC-detected GRB 191210A: Fermi-LAT Upper Limits
  63. Possible HAWC-detected GRB 191210A: Swift-XRT observations
  64. GRB 191207A: Possible GRB detected in Fermi-LAT blind search
  65. IceCube-191204A: No significant detection in HAWC
  66. Fermi-LAT Gamma-ray Observations of IceCube-191204A
  67. LIGO/Virgo S191205ah: No counterpart candidates in Fermi-LAT observations
  68. LIGO/Virgo S191204r: No counterpart candidates in Fermi-LAT observations
  69. LIGO/Virgo S191205ah: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  70. GRB 191130A: Swift-XRT observations
  71. IceCube-191204A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  72. LIGO/Virgo S191204r: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  73. GRB 191202A: Fermi-LAT detection
  74. GRB 191202A: Fermi GBM observation
  75. LIGO/Virgo S191129u: No counterpart candidates in Fermi-LAT observations
  76. LIGO/Virgo S191129u: no INTEGRAL data available
  77. IceCube-191122A: No significant detection in HAWC
  78. Fermi-LAT Gamma-ray Observations of IceCube-191122A
  79. GRB 191123A: Swift-XRT refined Analysis
  80. GRB 191122A: Swift-XRT refined Analysis
  81. IceCube-191119A: No significant detection in HAWC
  82. Fermi-LAT Gamma-ray Observations of IceCube-191119A
  83. IceCube-191119A - No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  84. LIGO/Virgo S191110af: Upper limits from Konus-Wind observations
  85. LIGO/Virgo S191110af: Swift XRT observations, no secure afterglow found
  86. LIGO/Virgo S191110af: No counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  87. LIGO/Virgo S191110af: No counterpart candidates in Fermi-LAT observations
  88. LIGO/Virgo S191110af: No counterpart candidates in INTEGRAL SPI-ACS, prompt observation
  89. LIGO/Virgo S191109d: No counterpart candidates in Fermi-LAT observations
  90. LIGO/Virgo S191109d: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  91. ZTF19abvizsw: Upper limits from Konus-Wind observations
  92. LIGO/Virgo S191105e: No counterpart candidates in Fermi-LAT observations
  93. GRB 191106A: Swift-XRT refined Analysis
  94. LIGO/Virgo S191105e: No counterpart candidates in INTEGRAL SPI-ACS and,IBIS prompt observation
  95. GRB 191101A: Swift/UVOT Upper Limits
  96. GRB 191101A: iTelescope optical limit
  97. GRB 191101A: Swift-XRT refined Analysis
  98. GRB 191031C: Swift-XRT refined Analysis
  99. GRB 191031D: Swift-XRT refined Analysis
  100. GRB 191031C: Fermi GBM detection

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