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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.

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

2722 results found.

  1. LIGO/Virgo S200114f: Candidates from the Zwicky Transient Facility
  2. LIGO/Virgo S200114f: Coverage and upper limits from MAXI/GSC observations
  3. LIGO/Virgo S200105ae : No significant candidates in TAROT - FRAM - GRANDMA observations.
  4. Fermi trigger No 600227156: Global MASTER-Net observations report
  5. Swift GRB200109.07: Global MASTER-Net observations report
  6. GRB 200109A: Swift detection of a burst
  7. LIGO/Virgo S200105ae: Candidates from the Zwicky Transient Facility
  8. GRB 200107B: Fermi GBM observation
  9. IceCube-200107A: No candidates from the Zwicky Transient Facility
  10. LIGO/Virgo S200105ae: Upper Limits from the Zwicky Transient Facility
  11. LIGO/Virgo S200105ae: no counterpart candidates in the Swift/BAT observations
  12. LIGO/Virgo S200105ae: Global MASTER-Net observations report
  13. LIGO/Virgo S200105ae: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  14. Fermi trigger No 599761015: Global MASTER-Net observations report
  15. IceCube Alert 200101.46: Global MASTER-Net observations report
  16. IPN triangulation of GRB 191227B (short)
  17. Fermi trigger No 598988276: Global MASTER-Net observations report
  18. LIGO/Virgo S191222n : No significant candidates in FRAM-TAROT-GRANDMA observations
  19. LIGO/Virgo S191222n: no counterpart candidate in SVOM/GWAC observations
  20. LIGO/Virgo S191216ap: No significant candidates found in Pan-STARRS observations
  21. LIGO/Virgo S191222n: no counterpart candidates in the Swift/BAT observations
  22. Baksan Neutrino Observatory Alert 191222.09: Global MASTER-Net observations report
  23. Fermi trigger No 598648473: Global MASTER-Net observations report
  24. LIGO/Virgo S191216ap: MASTER optical observation
  25. LIGO/Virgo S191216ap : No significant candidates in FRAM-TAROT-GRANDMA observations
  26. LIGO/Virgo S191213g: No counterpart candidate in the NOWT observations
  27. LIGO/Virgo S191215w : No significant candidates in TAROT - FRAM - GRANDMA observations.
  28. LIGO/Virgo S191216ap: no counterpart candidates in the Swift/BAT observations
  29. LIGO/Virgo S191216ap: No Candidates from the Zwicky Transient Facility
  30. LIGO/Virgo S191216ap: Coverage and upper limits from MAXI/GSC observations
  31. LIGO/Virgo S191216ap: Upper limits from Fermi-GBM Observations
  32. LIGO/Virgo S191215w: no counterpart candidates in the Swift/BAT observations
  33. LIGO/Virgo S191215w: Global MASTER-Net observations report
  34. LIGO/Virgo S191213g: Additional candidates from the Zwicky Transient Facility
  35. LIGO/Virgo S191213g: Lulin Follow-up Observations of ZTF19acykzsk/AT2019wqj
  36. LIGO/Virgo S191213g: Candidates from the Zwicky Transient Facility
  37. LIGO/Virgo S191213g: no counterpart candidates in the Swift/BAT observations
  38. LIGO/Virgo S191213g: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  39. LIGO/Virgo S191205ah: no counterpart candidate in SVOM/GWAC observations
  40. LIGO/Virgo S191205ah : No significant candidates in FRAM - TAROT – GRANDMA observations
  41. LIGO/Virgo S191205ah: no counterpart candidates in the Swift/BAT observations
  42. LIGO/Virgo S191129u : No significant candidates in FRAM-TAROT-GRANDMA observations.
  43. LIGO/Virgo S191204r: No significant candidates in FRAM-TAROT-GRANDMA observations.
  44. LIGO/Virgo S191205ah: Global MASTER-Net observations report
  45. LIGO/Virgo S191204r: no counterpart candidates in the Swift/BAT observations
  46. IceCube Alert 191204.95: Global MASTER-Net observations report
  47. GRB 191203A: Fermi GBM Final Real-time Localization
  48. Fermi trigger No 596786686: Global MASTER-Net observations report
  49. Fermi trigger No 596808579: Global MASTER-Net observations report
  50. Baksan Neutrino Observatory Alert 191128.17: Global MASTER-Net observations report
  51. Baksan Neutrino Observatory Alert 191127.25: Global MASTER-Net observations report
  52. LIGO/Virgo S191124be: Global MASTER-Net observations report
  53. IceCube-191119A: No significant detection in HAWC
  54. LIGO/Virgo S191110af: Upper limits from IceCube MeV neutrino searches
  55. LIGO/Virgo S191110af: no counterpart candidates in the Swift/BAT observations
  56. LIGO/Virgo S191109d: No significant candidates in FRAM-TAROT-GRANDMA observations
  57. LIGO/Virgo S191105e: No significant candidates in FRAM-TAROT-GRANDMA observations
  58. LIGO/Virgo S191109d: no counterpart candidates in the Swift/BAT observations
  59. LIGO/Virgo S191109d: Coverage and upper limits from MAXI/GSC observations
  60. LIGO/Virgo S191105e: no counterpart candidates in the Swift/BAT observations
  61. Fermi trigger No 594592184: Global MASTER-Net observations report
  62. Trigger 933276: Swift detection of further activity from SGR 1935+2154
  63. GRB 191101A: Swift-BAT refined analysis
  64. Fermi trigger No 594563923: Global MASTER-Net observations report
  65. Fermi trigger No 594557071: Global MASTER-Net observations report
  66. GRB 191031D: Zwicky Transient Facility Follow-Up of a Swift Short GRB (Trigger 594249816/191031891)
  67. GRB 191101A: Prompt enhanced Swift-XRT position
  68. GRB 191031D: COATLI Optical Observations
  69. IPN triangulation of GRB 191025B (short)
  70. GRB 191023A: MASTER optical observation
  71. Possible GRB 191025A: FRAM-Auger optical limit
  72. Swift Trigger 931384: possible GRB 191025A
  73. Fermi trigger No 592818648: Global MASTER-Net observations report
  74. ANTARES 191011A: MASTER optical observation befor and after trigger
  75. GRB 191011A: Fermi GBM Final Real-time Localization
  76. LIGO/Virgo S190930t: Continued Swift observations of AT2019sbk
  77. Konus-Wind observation of GRB 191004B
  78. GRB 191004A: Optical Detection with LCO
  79. LIGO/Virgo S190930s: no counterpart candidate in the SVOM/GWAC observations
  80. LIGO/Virgo S190930t: Magellan/IMACS imaging of Swift J224718-581442 (AT2019sbk)
  81. LIGO/Virgo S190930t: Swift discovery of Swift J224718-581442 (AT2019sbk): a fading UV transient with an X-ray counterpart
  82. LIGO/Virgo S190930t: AT2019rpn, AT2019rpj CrAO continued optical photometry
  83. GRB 191001B: Optical Upper Limits with LCO
  84. IceCube-191001A: Candidate Counterparts with the Zwicky Transient Facility
  85. LIGO/Virgo S190930t: AT2019rpn, AT2019rpj CrAO optical photometry
  86. LIGO/Virgo S190930s: No counterpart candidates in KAIT observations
  87. LIGO/Virgo S190930t: Candidates from the Zwicky Transient Facility
  88. Fermi trigger No 591604915: Global MASTER-Net observations report
  89. LIGO/Virgo S190930s: no counterpart candidates in the Swift/BAT observations
  90. LIGO/Virgo S190930t: no counterpart candidates in the Swift/BAT observations
  91. LIGO/Virgo S190930t: Upper limits from Fermi-GBM Observations
  92. LIGO/Virgo S190930t: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  93. Fermi trigger No 591391412: Global MASTER-Net observations report
  94. Fermi trigger No 591321287: Global MASTER-Net observations report
  95. LIGO/Virgo S190923y: No significant candidates in TAROT-GRANDMA observations
  96. LIGO/Virgo S190923y: no counterpart candidates in the Swift/BAT observations
  97. LIGO/Virgo S190924h: no counterpart candidates in the Swift/BAT observations
  98. LIGO/Virgo S190923y: INTEGRAL IBIS coded-masked imaging observations of part of the localization area and further all-sky upper limits
  99. IceCube-190922B: Identification of a Candidate Supernova from the Zwicky Transient Facility
  100. LIGO/Virgo S190923y: Upper limits from IceCube neutrino searches

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