Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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.

Advanced Search Examples (click to copy):

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

3616 results found.

  1. LIGO/Virgo/KAGRA S231206ca: Upper limits from Swift/BAT-GUANO
  2. LIGO/Virgo/KAGRA S231206ca: Updated Sky localization
  3. LIGO/Virgo/KAGRA S231206cc: Updated Sky localization and Source Classification
  4. LIGO/Virgo/KAGRA S231206cc: Identification of a GW compact binary merger candidate
  5. LIGO/Virgo/KAGRA S231206ca: Identification of a GW compact binary merger candidate
  6. LIGO/Virgo/KAGRA S231205c: One counterpart neutrino candidate event from an IceCube neutrino search
  7. LIGO/Virgo/KAGRA S231129ac: Upper limits from Swift/BAT-GUANO
  8. LIGO/Virgo/KAGRA S231129ac: Updated Sky localization
  9. LIGO/Virgo/KAGRA S231129ac: Identification of a GW compact binary merger candidate
  10. LIGO/Virgo/KAGRA S231127cg: Updated Sky localization
  11. LIGO/Virgo/KAGRA S231127cg: Identification of a GW compact binary merger candidate
  12. LIGO/Virgo/KAGRA S231118an: Updated Sky localization and EM Bright Classification
  13. LIGO/Virgo/KAGRA S231123cg: Identification of a GW compact binary merger candidate
  14. LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
  15. LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
  16. LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
  17. LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
  18. LIGO/Virgo/KAGRA S231119u: Updated Sky localization and Source Classification
  19. LIGO/Virgo/KAGRA S231118ab: Updated Sky localization and Source Classification
  20. LIGO/Virgo/KAGRA S231118d: Updated Sky localization and Source Classification
  21. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  22. LIGO/Virgo/KAGRA S231119u: One counterpart neutrino candidate from IceCube neutrino searches
  23. LIGO/Virgo/KAGRA S231119u: Identification of a GW compact binary merger candidate
  24. LIGO/Virgo/KAGRA S231118an: Identification of a GW compact binary merger candidate
  25. LIGO/Virgo/KAGRA S231118ab: Identification of a GW compact binary merger candidate
  26. LIGO/Virgo/KAGRA S231118d: Identification of a GW compact binary merger candidate
  27. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  28. GRB 231115A: Non-detection in low-latency of gravitational waves with LIGO/Virgo/KAGRA
  29. GRB 231106A: TESS identification of candidate optical counterpart
  30. LIGO/Virgo/KAGRA S231113bw: Updated Sky localization, EM Bright Classification, and Source Classification
  31. LIGO/Virgo/KAGRA S231113bw: Zwicky Transient Facility observations
  32. LIGO/Virgo/KAGRA S231114n: Updated Sky localization
  33. LIGO/Virgo/KAGRA S231113bw: GROWTH-India coverage and upper limits
  34. LIGO/Virgo S231113bw: upper limits from AGILE/MCAL
  35. LIGO/Virgo/KAGRA S231114n: Identification of a GW compact binary merger candidate
  36. LIGO/Virgo/KAGRA S231113bw: Upper limits from Fermi-GBM Observations
  37. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  38. LIGO/Virgo/KAGRA S231113bb: Updated Sky localization
  39. LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
  40. LIGO/Virgo/KAGRA S231113bw: Identification of a GW compact binary merger candidate
  41. LIGO/Virgo/KAGRA S231113bb: Identification of a GW compact binary merger candidate
  42. LIGO/Virgo/KAGRA S231112ag: Retraction of GW compact binary merger candidate
  43. LIGO/Virgo/KAGRA S231110g: Updated Sky localization
  44. LIGO/Virgo/KAGRA S231110g: Identification of a GW compact binary merger candidate
  45. LIGO/Virgo/KAGRA S231108u: Updated Sky localization
  46. LIGO/Virgo/KAGRA O4 Landscape
  47. LIGO/Virgo/KAGRA S231108u: Identification of a GW compact binary merger candidate
  48. LIGO/Virgo/KAGRA S231102w: Upper limits from Swift/BAT-GUANO
  49. LIGO/Virgo/KAGRA S231106y: one counterpart neutrino candidate from IceCube neutrino searches
  50. LIGO/Virgo/KAGRA S231104ac: Updated Sky localization
  51. LIGO/Virgo/KAGRA S231104ac: Identification of a GW compact binary merger candidate
  52. LIGO/Virgo/KAGRA S231102w: Updated Sky localization
  53. LIGO/Virgo/KAGRA S231102i: Global MASTER-Net observations report
  54. LIGO/Virgo/KAGRA S231102w: Identification of a GW compact binary merger candidate
  55. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  56. LIGO/Virgo/KAGRA S231029y: Upper limits from Swift/BAT-GUANO
  57. LIGO/Virgo/KAGRA S231030av: Retraction of GW compact binary merger candidate
  58. LIGO/Virgo/KAGRA S231029y: One counterpart neutrino candidate from IceCube neutrino searches
  59. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  60. LIGO/Virgo/KAGRA S231029y: Identification of a GW compact binary merger candidate
  61. LIGO/Virgo/KAGRA S231029k: Global MASTER-Net observations report
  62. LIGO/Virgo/KAGRA S231028bg: Updated Sky localization
  63. LIGO/Virgo/KAGRA S231028bg: Identification of a GW compact binary merger candidate
  64. LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
  65. LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
  66. LIGO/Virgo/KAGRA S231025a: two counterpart neutrino candidates from IceCube neutrino searches
  67. LIGO/Virgo/KAGRA S231020bw: Upper limits from Swift/BAT-GUANO
  68. LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
  69. LIGO/Virgo/KAGRA S231020bw: Updated Sky localization
  70. LIGO/Virgo/KAGRA S231020ba: Updated Sky localization and EM Bright Classification
  71. LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
  72. LIGO/Virgo/KAGRA S231020bw: Identification of a GW compact binary merger candidate
  73. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  74. LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
  75. LIGO/Virgo/KAGRA S231018cb: One counterpart neutrino candidate event from an IceCube neutrino search
  76. LIGO/Virgo/KAGRA S231014r: Upper limits from Swift/BAT-GUANO
  77. LIGO/Virgo/KAGRA S231014r: Identification of a GW compact binary merger candidate
  78. LIGO/Virgo/KAGRA S231001aq: Updated Sky localization
  79. LIGO/Virgo/KAGRA S231005j: Upper limits from Swift/BAT-GUANO
  80. LIGO/Virgo/KAGRA S231008ap: Updated Sky localization
  81. LIGO/Virgo/KAGRA S231008ap: Identification of a GW compact binary merger candidate
  82. LIGO/Virgo/KAGRA S231005ah: Updated Sky localization
  83. LIGO/Virgo/KAGRA S231005ah: Identification of a GW compact binary merger candidate
  84. LIGO/Virgo/KAGRA S231005j: Updated Sky localization
  85. LIGO/Virgo/KAGRA S231005j: Identification of a GW compact binary merger candidate
  86. LIGO/Virgo/KAGRA S231001aq: Upper limits from Swift/BAT-GUANO
  87. LIGO/Virgo/KAGRA S230930al: Upper limits from Swift/BAT-GUANO
  88. LIGO/Virgo/KAGRA S230928cb: Upper limits from Swift/BAT-GUANO
  89. LIGO/Virgo/KAGRA S231001aq: Updated Sky localization
  90. LIGO/Virgo/KAGRA S230930al: Updated Sky localization
  91. LIGO/Virgo/KAGRA S230928cb: Updated Sky localization
  92. LIGO/Virgo/KAGRA S231001aq: Identification of a GW compact binary merger candidate
  93. LIGO/Virgo/KAGRA S230930al: Identification of a GW compact binary merger candidate
  94. LIGO/Virgo/KAGRA S230928cb: Identification of a GW compact binary merger candidate
  95. LIGO/Virgo/KAGRA S230927be: Updated Sky localization
  96. LIGO/Virgo/KAGRA S230927l: Updated Sky localization
  97. LIGO/Virgo/KAGRA S230927be: Identification of a GW compact binary merger candidate
  98. LIGO/Virgo/KAGRA S230927l: Identification of a GW compact binary merger candidate
  99. LIGO/Virgo/KAGRA S230922q: Updated Sky localization
  100. LIGO/Virgo/KAGRA S230924an: Upper limits from Swift/BAT-GUANO

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov