Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

28256 results found.

  1. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  2. Swift Trigger 1235109: a possible GRB 240606A
  3. LIGO/Virgo/KAGRA S240601co: Updated Sky localization
  4. GRB 240604A: GECAM detection of a long burst
  5. GRB 240529A: SAO RAS optical observations
  6. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  7. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  8. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  9. GRB 240603C: BALROG localization (Fermi Trigger 739102156 / GRB 240603423)
  10. Swift Trigger 1232465: consistent with noise
  11. GRB 240529A: MASTER prompt OT detection
  12. GRB 240603A: GECAM detection of a short burst
  13. GRB 240529A: continued SAO RAS optical observations
  14. GRB 240529A: OSN optical detection
  15. The EP-WXT source triggered on June 1st is likely a flaring star
  16. GRB 240529A: further SAO RAS optical observations
  17. LIGO/Virgo/KAGRA S240601aj: Updated Sky localization
  18. LIGO/Virgo/KAGRA S240601co: Identification of a GW compact binary merger candidate
  19. Swift Trigger 1232465 is not a GRB
  20. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  21. LIGO/Virgo/KAGRA S240530a: Updated Sky localization
  22. LXT 240528A: GSP optical upper limit
  23. GRB 240529A: 1.3m DFOT Optical observations
  24. LIGO/Virgo/KAGRA S240527en: Updated Sky localization
  25. LIGO/Virgo/KAGRA S240601aj: Identification of a GW compact binary merger candidate
  26. GRB 240531A: AstroSat CZTI detection of a short burst
  27. GRB 240529A : Mondy optical observations
  28. GRB 240529A: SAO RAS optical observations
  29. LIGO/Virgo/KAGRA S240531bp: Updated Sky localization
  30. LIGO/Virgo/KAGRA S240531bp: Identification of a GW compact binary merger candidate
  31. GRB 240529A: GROWTH-India optical follow-up
  32. GRB 240529A: T193/MISTRAL observations
  33. GRB 240529A: Redshift from GTC/OSIRIS+
  34. GRB 240529A: AKO Optical Afterglow Detection
  35. LIGO/Virgo/KAGRA S240530a: Identification of a GW compact binary merger candidate
  36. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  37. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  38. GRB 240529A: J-band detections with WINTER
  39. GRB 240529A: Skynet Optical Observations
  40. LXT 240528A: LEIA detection of a fast X-ray transient
  41. GRB 240529A: Swift-BAT refined analysis
  42. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  43. GRB 240529A: Swift-XRT refined Analysis
  44. GRB 240529A: Swift/UVOT Detection
  45. GRB 240529A: NOT optical observations
  46. GRB 240527B: Swift-XRT afterglow detection
  47. GRB 240529A: Enhanced Swift-XRT position
  48. GRB 240529A: Swift detection of a burst with an optical counterpart
  49. LIGO/Virgo/KAGRA S240527fv: Updated Sky localization
  50. GRB 240527B: Fermi GBM Observation
  51. LIGO/Virgo/KAGRA S240527fv: Identification of a GW compact binary merger candidate
  52. LIGO/Virgo/KAGRA S240527en: Identification of a GW compact binary merger candidate
  53. GRB 240527B: BALROG localization (Fermi Trigger 738511436 / GRB 240527586)
  54. GRB 240523A: Swift-BAT refined analysis
  55. LIGO/Virgo/KAGRA S240525p: Updated Sky localization
  56. LIGO/Virgo/KAGRA S240525p: Identification of a GW compact binary merger candidate
  57. GRB 240523A: Swift-XRT refined Analysis
  58. GRB 240523A: Enhanced Swift-XRT position
  59. GRB 240523A: Swift detection of a burst
  60. GRB 240521B: Fermi GBM Observation
  61. Fermi GBM Sub-Threshold Detection of GRB 240516B
  62. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
  63. LIGO/Virgo/KAGRA S240520cv: Updated Sky localization and EM Bright Classification
  64. EP240518a: GSP optical upper limit
  65. GRB 240521A: GECAM-B detection of a long burst
  66. GRB 240516B: AstroSat CZTI detection
  67. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  68. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  69. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  70. LIGO/Virgo/KAGRA S240520cv: Identification of a GW compact binary merger candidate
  71. IceCube-Cascade 240518A: Upper limits from a search for additional neutrino events in IceCube
  72. GRB 240514B: VZLUSAT-2 detection
  73. GRB 240504A: VZLUSAT-2 detection
  74. GRB 240502A: VZLUSAT-2 detection
  75. GRB 240516A: Swift/UVOT Upper Limits
  76. EP240518a: possibly identified with a flare star by EP-FXT
  77. GRB 240519A: BALROG localization (Fermi Trigger 737788024 / GRB 240519213)
  78. EP240518a: EP-WXT detection of a new X-ray transient
  79. LIGO/Virgo/KAGRA S240514c: Updated Sky localization
  80. GRB 240516A: Swift-BAT refined analysis
  81. IPN triangulation of GRB 240514B (short)
  82. GRB 240516A: Swift-XRT refined Analysis
  83. GRB 240516A: Fermi GBM Observation
  84. GRB 240511A: Observations from GTC/OSIRIS+
  85. GRB 240516A: Swift detection of a burst
  86. GRB 240511A: radio detection of afterglow candidate
  87. MAXI GRB240514.78: Global MASTER-Net observations report
  88. GRB 240514E: MAXI/GSC detection of a probable afterglow
  89. LIGO/Virgo/KAGRA S240514x: Updated Sky localization
  90. LIGO/Virgo/KAGRA S240515m: Identification of a GW compact binary merger candidate
  91. GRB 240513A: Fermi GBM observation
  92. GRB 240513A: Swift-XRT observations
  93. LIGO/Virgo/KAGRA S240513ei: Updated Sky localization
  94. LIGO/Virgo/KAGRA S240514x: Identification of a GW compact binary merger candidate
  95. LIGO/Virgo/KAGRA S240514c: Identification of a GW compact binary merger candidate
  96. transient: Xinglong Nearby Galaxy Supernova Survey detection of AT2024iss
  97. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  98. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  99. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  100. LIGO/Virgo/KAGRA S240513ei: Identification of a GW compact binary merger candidate

Advanced

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