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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"

342 results found.

  1. IceCube-Cascade 211128A: Upper limits from a search for additional neutrino events in IceCube
  2. IceCube-211125A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  3. IceCube-211123A: Upper limits from a search for additional neutrino events in IceCube
  4. HAWC-211123A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  5. Konus-Wind observation of the recent SGR 1935+2154 activity
  6. IceCube-210730A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  7. IceCube-210717A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  8. GRB 210709A: AstroSat CZTI detection
  9. INTEGRAL detection of a burst from SGR 1935+2154
  10. IceCube-210516A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  11. IceCube-210510A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  12. IceCube-210629A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  13. GRB 210531A: AstroSat CZTI detection
  14. Fermi GRB 210510A: Global MASTER-Net observations report
  15. Fermi-LAT Gamma-ray Observations of IceCube-210503A and detection of a new gamma-ray source, Fermi J0931.9+3633
  16. GRB 210402A: MASTER prompt and follow up optical observation
  17. Fermi-LAT Gamma-ray Observations of IceCube-210210A
  18. IceCube-210210A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  19. Konus-Wind detection of two bright bursts from SGR 1935+2154
  20. NuEm-210111A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  21. IceCube-201222A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  22. IceCube-201221A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  23. IceCube-201209A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  24. IceCube-201130A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  25. IceCube-201120A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  26. IceCube-201115A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  27. IceCube-201114A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  28. VLASS identifies possible radio counterparts to IceCube-201115A, including a bright BL Lac candidate
  29. IceCube-201021A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  30. IceCube-201014A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  31. IceCube-201007A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  32. IceCube-200926B: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  33. IceCube-200929A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  34. Fermi-LAT Gamma-ray Observations of IceCube-200926B
  35. IceCube-200921A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  36. IceCube-200916A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  37. Fermi-LAT Gamma-ray Observations of IceCube-200916A
  38. IceCube-200911A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  39. IceCube-200806A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  40. Fermi-LAT Gamma-ray Observations of IceCube-200806A
  41. IceCube-200615A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  42. IceCube-200614A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  43. Fermi-LAT Gamma-ray Observations of IceCube-200530A
  44. IceCube-200530A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  45. Fermi-LAT Gamma-ray Observations of IceCube-190523A
  46. Fermi-LAT Gamma-ray Observations of IceCube-200512A
  47. IceCube-200512A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  48. Konus-Wind observation of SGR 1935+2154 activity on 2020 May 10
  49. IceCube-200425A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  50. IceCube-200421A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  51. Fermi-LAT Gamma-ray Observations of IceCube-200410A
  52. IceCube-200410A: Possible associated excess in INTEGRAL SPI-ACS prompt observation
  53. LIGO/Virgo S200316bj: No counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  54. LIGO/Virgo S200311bg: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  55. LIGO/Virgo S200302c: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  56. GRB 200228B: Mondy, TSHAO, AbAO and CrAO optical observations, afterglow candidate
  57. Fermi-LAT Gamma-ray Observations of IceCube-200227A
  58. IceCube-200227A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  59. LIGO/Virgo S200225q: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  60. LIGO/Virgo S200224ca: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  61. GRB 200219A, Swift-BAT refined analysis
  62. LIGO/Virgo S200219ac: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  63. LIGO/Virgo S200213t: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  64. LIGO/Virgo S200208q: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  65. LIGO/Virgo S200128d: no counterpart candidate in SVOM/GWAC observations
  66. LIGO/Virgo S200129m: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  67. LIGO/Virgo S200128d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  68. IceCube-200120A: no counterpart candidates in INTEGRAL SPI-ACS and,IBIS prompt observation
  69. IceCube-200117A: no counterpart candidates in INTEGRAL SPI-ACS and,IBIS prompt observation
  70. LIGO/Virgo S200115j: no counterpart candidate in SVOM/GWAC observations
  71. LIGO/Virgo S200114f: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  72. LIGO/Virgo S200112r: upper limits from AGILE/GRID observations
  73. Fermi-LAT ANTARES coincidence: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  74. Fermi-LAT Gamma-ray Observations of IceCube-200107A
  75. IceCube-200107A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  76. LIGO/Virgo S200105ae: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  77. Fermi-LAT Gamma-ray Observations of IceCube-191231A
  78. IceCube-191231A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  79. Fermi-LAT Gamma-ray Observations of IceCube-191215A
  80. LIGO/Virgo S191215w: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  81. LIGO/Virgo S191215w: Identification of a GW compact binary merger candidate
  82. IceCube-191215A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  83. LIGO/Virgo S191213g: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  84. LIGO/Virgo S191204r: No counterpart candidates in Fermi-LAT observations
  85. LIGO/Virgo S191205ah: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  86. IceCube-191204A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  87. LIGO/Virgo S191204r: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  88. Fermi-LAT Gamma-ray Observations of IceCube-191119A
  89. IceCube-191119A - No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  90. LIGO/Virgo S191110af: Potential pulsar counterparts
  91. Konus-Wind observation of the recent SGR 1935+2154 activity
  92. LIGO/Virgo S191110af: No counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  93. LIGO/Virgo S191110af: No counterpart candidates in INTEGRAL SPI-ACS, prompt observation
  94. LIGO/Virgo S191109d: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  95. LIGO/Virgo S191105e: No counterpart candidates in INTEGRAL SPI-ACS and,IBIS prompt observation
  96. GRB 191019A: Swift-XRT observations
  97. IceCube-191001A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  98. LIGO/Virgo S190930t: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  99. LIGO/Virgo S190930s: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  100. Fermi-LAT Gamma-ray Observations of IceCube-190922B

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