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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.

Lucene Examples (click to copy):

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

321 results found.

  1. IceCube-250416A: Upper limits from a search for additional neutrino events in IceCube
  2. GRB 250331C: Swift/UVOT Upper Limits
  3. IceCube-250330A: Upper limits from a search for additional neutrino events in IceCube
  4. IceCube-250309A: Upper limits from a search for additional neutrino events in IceCube
  5. IceCube-250302A: Upper limits from a search for additional neutrino events in IceCube
  6. IceCube-Cascade 250215A: Upper limits from a search for additional neutrino events in IceCube
  7. LIGO/Virgo/KAGRA S250206dm: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  8. GECAM-A detection of a bright burst from SGR 1E1841-045
  9. Konus-Wind detection of a bright burst from SGR 1E1841-045 on 2025 January 23
  10. IPN triangulation of a bright burst from SGR 1E1841-045
  11. IceCube-250102A: Upper limits from a search for additional neutrino events in IceCube
  12. Fermi Gamma-ray Burst Monitor trigger 755277791/241207641 is not a GRB
  13. GRB 241130A: EIRSAT-1 GMOD Detection
  14. IceCube-241127A: Upper limits from a search for additional neutrino events in IceCube
  15. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  16. EP241113a: Swift XRT weak detection
  17. IceCube-241113A: Upper limits from a search for additional neutrino events in IceCube
  18. SVOM/GRM detection of a short burst from SGR 1E1841-045
  19. INTEGRAL detection of a burst from 1E 1841-045
  20. EP241107a: EP on-board trigger and autonomous follow-up observation
  21. EP241025a (GRB 241025A): EP observations update
  22. GRB241017A: TOO Observations by SVOM/MXT
  23. IceCube-241006A: Upper limits from a search for additional neutrino events in IceCube
  24. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  25. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  26. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  27. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  28. GRB 240824A: Swift/UVOT Upper Limits
  29. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  30. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  31. GECAM-B observation of a short burst from SGR 1E 1841-045 / Kes 73
  32. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  33. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  34. Trigger 1249653: Swift detection of SGR 1E 1841-045 / Kes 73
  35. IceCube-Cascade 240518A: Upper limits from a search for additional neutrino events in IceCube
  36. LIGO/Virgo S240422ed: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  37. IceCube-Cascade 240416A: Upper limits from a search for additional neutrino events in IceCube
  38. IceCube-240412A: Upper limits from a search for additional neutrino events in IceCube
  39. IceCube-240327A: Upper limits from a search for additional neutrino events in IceCube
  40. IceCube-240229A: Upper limits from a search for additional neutrino events in IceCube
  41. IceCube-240204A: Upper limits from a search for additional neutrino events in IceCube
  42. IceCube-240123A: Upper limits from a search for additional neutrino events in IceCube
  43. GRB 240106A: Glowbug gamma-ray detection
  44. IceCube-240105A: Upper limits from a search for additional neutrino events in IceCube
  45. IceCube-231211A: Upper limits from a search for additional neutrino events in IceCube
  46. Fermi GRB 231108A: Global MASTER-Net observations report
  47. LIGO/Virgo/KAGRA S231014r: Identification of a GW compact binary merger candidate
  48. LIGO/Virgo S230802aq: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  49. IceCube-230727A: Upper limits from a search for additional neutrino events in IceCube
  50. IceCube-230725A: Upper limits from a search for additional neutrino events in IceCube
  51. IceCube-230708A: Upper limits from a search for additional neutrino events in IceCube
  52. IceCube-230707B: Upper limits from a search for additional neutrino events in IceCube
  53. LIGO/Virgo/KAGRA S230527c: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  54. IceCube-Cascade 230610A: Upper limits from a search for additional neutrino events in IceCube
  55. LIGO/Virgo/KAGRA S230609u: Identification of a GW compact binary merger candidate
  56. LIGO/Virgo/KAGRA S230529ay: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  57. LIGO/Virgo/KAGRA S230518h: Upper limits from Glowbug gamma-ray observations
  58. LIGO/Virgo S230518h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  59. IceCube-Cascade 230511A: Upper limits from a search for additional neutrino events in IceCube
  60. IceCube-Cascade 230430A: Upper limits from a search for additional neutrino events in IceCube
  61. IceCube-230416A: Upper limits from a search for additional neutrino events in IceCube
  62. IceCube-230405A: Upper limits from a search for additional neutrino events in IceCube
  63. INTEGRAL detection of a burst from SGR 1806-200
  64. GRB 230307A: soft X-ray detection with LEIA
  65. GRB 230307A: GECAM detection of an extremely bright burst
  66. IceCube-230220A: Upper limits from a search for additional neutrino events in IceCube
  67. IceCube-230201A: Upper limits from a search for additional neutrino events in IceCube
  68. IceCube-230122A: Upper limits from a search for additional neutrino events in IceCube
  69. Fermi-LAT gamma-ray observations of IceCube-230112A
  70. IceCube-221229A: Upper limits from a search for additional neutrino events in IceCube
  71. Fermi-LAT gamma-ray observations of IceCube-221223A
  72. IceCube-221216A: Upper limits from a search for additional neutrino events in IceCube
  73. IceCube-221124A: Upper limits from a search for additional neutrino events in IceCube
  74. IceCube-221104A: Upper limits from a search for additional neutrino events in IceCube
  75. Konus-Wind observation of the recent SGR 1935+2154 activity
  76. INTEGRAL detection of a burst from SGR J1935+2154
  77. IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
  78. IceCube-Cascade 220826A: Upper limits from a search for additional neutrino events in IceCube
  79. IceCube-220629A: Upper limits from a search for additional neutrino events in IceCube
  80. IceCube-220627A: Upper limits from a search for additional neutrino events in IceCube
  81. IceCube-Cascade 220625A: Upper limits from a search for additional neutrino events in IceCube
  82. GRB 220518A: Swift/UVOT Detection
  83. IceCube-220509A: Upper limits from a search for additional neutrino events in IceCube
  84. IceCube-220425A: Upper limits from a search for additional neutrino events in IceCube
  85. IceCube-220424A: Upper limits from a search for additional neutrino events in IceCube
  86. IceCube-220421A: Upper limits from a search for additional neutrino events in IceCube
  87. IceCube-220317A: Upper limits from a search for additional neutrino events in IceCube
  88. IceCube-220306A: Upper limits from a search for additional neutrino events in IceCube
  89. IceCube-220303A: Upper limits from a search for additional neutrino events in IceCube
  90. GRB 220228A: Fermi-LAT detection
  91. GRB 220101A: The first example of a Petanova
  92. IceCube-220205A: Upper limits from a search for additional neutrino events in IceCube
  93. IceCube-211216A: Upper limits from a search for additional neutrino events in IceCube
  94. IceCube-211216A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  95. IceCube-211208A: Upper limits from a search for additional neutrino events in IceCube
  96. IceCube-211208A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  97. IceCube-Cascade 211128A: Upper limits from a search for additional neutrino events in IceCube
  98. IceCube-211125A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  99. IceCube-211123A: Upper limits from a search for additional neutrino events in IceCube
  100. HAWC-211123A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation

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