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"

4056 results found.

  1. LIGO/Virgo/KAGRA S240825ar: Upper limits from Swift/BAT-GUANO
  2. LIGO/Virgo/KAGRA S240807h: Upper limits from Swift/BAT-GUANO
  3. LIGO/Virgo/KAGRA S240902bq: Updated Sky localization
  4. LIGO/Virgo/KAGRA S240902bq: Identification of a GW compact binary merger candidate
  5. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  6. LIGO/Virgo/KAGRA S240830gn: Updated Sky localization and EM Bright Classification
  7. LIGO/Virgo/KAGRA S240830gn: Identification of a GW compact binary merger candidate
  8. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  9. LIGO/Virgo/KAGRA S240825ar: Updated Sky localization
  10. LIGO/Virgo/KAGRA S240825ar: Identification of a GW compact binary merger candidate
  11. GRB 240824B: Swift/BAT arcminute localization of a burst
  12. GRB240821A: EIRSAT-1 GMOD Detection
  13. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  14. LIGO/Virgo/KAGRA S240813d: Updated Sky localization
  15. LIGO/Virgo/KAGRA S240813d: Identification of a GW compact binary merger candidate
  16. LIGO/Virgo/KAGRA S240813c: Updated Sky localization
  17. LIGO/Virgo/KAGRA S240813c: Identification of a GW compact binary merger candidate
  18. IceCube-240808A: Upper limits from a search for additional neutrino events in IceCube
  19. LIGO/Virgo/KAGRA S240807h: Updated Sky localization and EM Bright Classification
  20. EP240807a: STEP/T80S optical limits
  21. S240807h: Identification of a GW compact binary merger candidate
  22. LIGO/Virgo/KAGRA S240615dg: GRAWITA wide-field optical observations
  23. GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
  24. IceCube-240725A: Upper limits from a search for additional neutrino events in IceCube
  25. IceCube-240721A: Upper limits from a search for additional neutrino events in IceCube
  26. LIGO/Virgo/KAGRA S240716b: Upper limits from Swift/BAT-GUANO
  27. LIGO/Virgo/KAGRA S240703ad: Upper limits from Swift/BAT-GUANO
  28. LIGO/Virgo/KAGRA S240716b: Updated Sky localization
  29. LIGO/Virgo/KAGRA S240716b: Identification of a GW compact binary merger candidate
  30. LIGO/Virgo/KAGRA S240711cm: Coverage and upper limits from MAXI/GSC observations
  31. LIGO/Virgo/KAGRA S240627by: Updated Sky localization and EM Bright Classification
  32. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  33. LIGO/Virgo/KAGRA S240705at: Updated Sky localization
  34. LIGO/Virgo/KAGRA S240705at: Identification of a GW compact binary merger candidate
  35. LIGO/Virgo/KAGRA S240703ad: Updated Sky localization
  36. LIGO/Virgo/KAGRA S240703ad: Identification of a GW compact binary merger candidate
  37. LIGO/Virgo/KAGRA S240422ed: Updated significance estimate
  38. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  39. LIGO/Virgo/KAGRA S240630t: Updated Sky localization
  40. LIGO/Virgo/KAGRA S240629by: Updated Sky localization
  41. LIGO/Virgo/KAGRA S240630t: Identification of a GW compact binary merger candidate
  42. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  43. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  44. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  45. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  46. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  47. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  48. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  49. LIGO/Virgo/KAGRA S240624cd: Retraction of GW unmodeled transient candidate
  50. LIGO/Virgo/KAGRA S240623dg: Retraction of GW compact binary merger candidate
  51. LIGO/Virgo/KAGRA S240622h: Updated Sky localization and Source Classification
  52. LIGO/Virgo/KAGRA S240621em: Updated Sky localization and Source Classification
  53. LIGO/Virgo/KAGRA S240621dy: Updated Sky localization and Source Classification
  54. LIGO/Virgo/KAGRA S240621eb: Updated Sky localization and Source Classification
  55. LIGO/Virgo/KAGRA S240622h: Identification of a GW compact binary merger candidate
  56. LIGO/Virgo/KAGRA S240621em: Identification of a GW compact binary merger candidate
  57. LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
  58. LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
  59. EP240617a: STEP/T80S optical limits
  60. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  61. LIGO/Virgo/KAGRA S240615dg: Updated Sky localization
  62. LIGO/Virgo/KAGRA S240618ah: Updated Sky localization
  63. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  64. LIGO/Virgo/KAGRA S240618ah: Identification of a GW compact binary merger candidate
  65. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  66. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  67. LIGO/Virgo/KAGRA S240615ea: Updated Sky localization
  68. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  69. LIGO/Virgo/KAGRA S240615ea: Identification of a GW compact binary merger candidate
  70. LIGO/Virgo/KAGRA S240615dg: Identification of a GW compact binary merger candidate
  71. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  72. LIGO/Virgo/KAGRA S240601co: Updated Sky localization
  73. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  74. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  75. LIGO/Virgo/KAGRA S240601aj: Updated Sky localization
  76. LIGO/Virgo/KAGRA S240601co: Identification of a GW compact binary merger candidate
  77. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  78. LIGO/Virgo/KAGRA S240530a: Updated Sky localization
  79. LIGO/Virgo/KAGRA S240527en: Updated Sky localization
  80. LIGO/Virgo/KAGRA S240601aj: Identification of a GW compact binary merger candidate
  81. LIGO/Virgo/KAGRA S240531bp: Updated Sky localization
  82. LIGO/Virgo/KAGRA S240531bp: Identification of a GW compact binary merger candidate
  83. LIGO/Virgo/KAGRA S240530a: Identification of a GW compact binary merger candidate
  84. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  85. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  86. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  87. LIGO/Virgo/KAGRA S240527fv: Updated Sky localization
  88. LIGO/Virgo/KAGRA S240527fv: Identification of a GW compact binary merger candidate
  89. LIGO/Virgo/KAGRA S240527en: Identification of a GW compact binary merger candidate
  90. LIGO/Virgo/KAGRA S240525p: Updated Sky localization
  91. LIGO/Virgo/KAGRA S240525p: Identification of a GW compact binary merger candidate
  92. LIGO/Virgo/KAGRA S240520cv: Updated Sky localization and EM Bright Classification
  93. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  94. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  95. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  96. LIGO/Virgo/KAGRA S240520cv: Identification of a GW compact binary merger candidate
  97. LIGO/Virgo/KAGRA S240514c: Updated Sky localization
  98. LIGO/Virgo/KAGRA S240422ed: GRID non-detection and upper limits
  99. Fermi Gamma-ray Burst Monitor list of triggers that are not a GRB
  100. LIGO/Virgo/KAGRA S240514x: Updated Sky localization

Advanced

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