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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').

307 results found.

  1. IceCube-210629A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  2. Fermi-LAT Gamma-ray Observations of IceCube-210503A and detection of a new gamma-ray source, Fermi J0931.9+3633
  3. GRB 210402A: MASTER prompt and follow up optical observation
  4. Fermi-LAT Gamma-ray Observations of IceCube-210210A
  5. IceCube-210210A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  6. Konus-Wind detection of two bright bursts from SGR 1935+2154
  7. NuEm-210111A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  8. IceCube-201222A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  9. IceCube-201221A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  10. IceCube-201209A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  11. IceCube-201130A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  12. IceCube-201120A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  13. IceCube-201115A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  14. IceCube-201114A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  15. VLASS identifies possible radio counterparts to IceCube-201115A, including a bright BL Lac candidate
  16. IceCube-201021A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  17. IceCube-201014A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  18. IceCube-201007A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  19. IceCube-200926B: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  20. IceCube-200929A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  21. Fermi-LAT Gamma-ray Observations of IceCube-200926B
  22. IceCube-200921A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  23. IceCube-200916A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  24. Fermi-LAT Gamma-ray Observations of IceCube-200916A
  25. IceCube-200911A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  26. IceCube-200806A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  27. Fermi-LAT Gamma-ray Observations of IceCube-200806A
  28. IceCube-200615A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  29. IceCube-200614A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  30. Fermi-LAT Gamma-ray Observations of IceCube-200530A
  31. IceCube-200530A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  32. Fermi-LAT Gamma-ray Observations of IceCube-190523A
  33. Fermi-LAT Gamma-ray Observations of IceCube-200512A
  34. IceCube-200512A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  35. Konus-Wind observation of SGR 1935+2154 activity on 2020 May 10
  36. IceCube-200425A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  37. IceCube-200421A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  38. Fermi-LAT Gamma-ray Observations of IceCube-200410A
  39. IceCube-200410A: Possible associated excess in INTEGRAL SPI-ACS prompt observation
  40. LIGO/Virgo S200316bj: No counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  41. LIGO/Virgo S200311bg: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  42. LIGO/Virgo S200302c: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  43. Fermi-LAT Gamma-ray Observations of IceCube-200227A
  44. IceCube-200227A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  45. LIGO/Virgo S200225q: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  46. LIGO/Virgo S200224ca: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  47. LIGO/Virgo S200219ac: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  48. LIGO/Virgo S200213t: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  49. LIGO/Virgo S200208q: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  50. LIGO/Virgo S200129m: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  51. LIGO/Virgo S200128d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  52. IceCube-200120A: no counterpart candidates in INTEGRAL SPI-ACS and,IBIS prompt observation
  53. IceCube-200117A: no counterpart candidates in INTEGRAL SPI-ACS and,IBIS prompt observation
  54. LIGO/Virgo S200114f: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  55. LIGO/Virgo S200112r: upper limits from AGILE/GRID observations
  56. Fermi-LAT ANTARES coincidence: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  57. Fermi-LAT Gamma-ray Observations of IceCube-200107A
  58. IceCube-200107A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  59. LIGO/Virgo S200105ae: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  60. Fermi-LAT Gamma-ray Observations of IceCube-191231A
  61. IceCube-191231A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  62. Fermi-LAT Gamma-ray Observations of IceCube-191215A
  63. LIGO/Virgo S191215w: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  64. LIGO/Virgo S191215w: Identification of a GW compact binary merger candidate
  65. IceCube-191215A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  66. LIGO/Virgo S191213g: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  67. LIGO/Virgo S191204r: No counterpart candidates in Fermi-LAT observations
  68. LIGO/Virgo S191205ah: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  69. IceCube-191204A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  70. LIGO/Virgo S191204r: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  71. Fermi-LAT Gamma-ray Observations of IceCube-191119A
  72. IceCube-191119A - No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  73. LIGO/Virgo S191110af: Potential pulsar counterparts
  74. Konus-Wind observation of the recent SGR 1935+2154 activity
  75. LIGO/Virgo S191110af: No counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  76. LIGO/Virgo S191110af: No counterpart candidates in INTEGRAL SPI-ACS, prompt observation
  77. LIGO/Virgo S191109d: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  78. LIGO/Virgo S191105e: No counterpart candidates in INTEGRAL SPI-ACS and,IBIS prompt observation
  79. IceCube-191001A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  80. LIGO/Virgo S190930t: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  81. LIGO/Virgo S190930s: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  82. Fermi-LAT Gamma-ray Observations of IceCube-190922B
  83. LIGO/Virgo S190924h: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  84. LIGO/Virgo S190923y: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  85. IceCube-190922A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  86. HAWC-190916A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  87. LIGO/Virgo S190915ak: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  88. LIGO/Virgo S190910h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  89. LIGO/Virgo S190910d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  90. LIGO/Virgo S190901ap: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  91. LIGO/Virgo S190828l: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  92. LIGO/Virgo S190828j: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  93. Fermi GBM-190816: Location-dependent upper limits from INTEGRAL/SPI-ACS prompt observation
  94. IceCube-190819A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  95. HAWC-190806A: upper limits from INTEGRAL SPI-ACS and IBIS prompt observation
  96. IceCube 190730A: one weakly associated counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  97. Fermi-LAT Gamma-ray Observations of IceCube-190712A
  98. Fermi-LAT Gamma-ray Observations of IceCube-190504A
  99. LIGO/Virgo S190426c: Fermi-LAT search for a high-energy gamma-ray counterpart
  100. INTEGRAL observations of the events in the GWTC-1 catalog

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