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"

19938 results found.

  1. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  2. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  3. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  4. Konus-Wind detection of GRB 240811A
  5. GRB 240811A: Swift-BAT refined analysis
  6. GRB 240809A: Swift-BAT refined analysis
  7. GRB 240811A: Bassano Bresciano Observatory upper limit
  8. GRB 240811A: Swift-XRT refined Analysis
  9. GRB 240811A: Swift/UVOT Upper Limits
  10. GRB 240811A: LCOGT Optical Upper Limit
  11. GRB 240811A: Enhanced Swift-XRT position
  12. Konus-Wind detection of GRB 240809A
  13. Swift GRB 240811A: Global MASTER-Net observations report
  14. GRB 240811A: Swift detection of a burst
  15. GRB 240809A: Bassano Bresciano Observatory optical observations
  16. GRB 240809A: KAIT optical observations
  17. GRB 240809A: GIT afterglow observations
  18. GRB 240809A: Swift/UVOT Detection
  19. GRB 240809A: Swift-XRT refined Analysis
  20. IPN triangulation of GRB 240807A / EP 240807a
  21. Swift GRB 240809A: Global MASTER-Net observations report
  22. GRB 240809A: JinShan optical observations
  23. GRB 240809A: Enhanced Swift-XRT position
  24. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  25. GRB 240809A: SVOM/GRM observation
  26. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  27. GRB 240805A: ATCA Radio Upper Limits
  28. GRB 240805B: GIT optical upper limit
  29. GRB 240805B: Swift-BAT refined analysis
  30. GRB 240805A: Swift-BAT refined analysis
  31. Konus-Wind detection of GRB 240805A
  32. GRB 240805B Bassano Bresciano Observatory upper limit
  33. GRB240805A: Fermi GBM Observation
  34. GRB 240805B: JinShan optical afterglow detection
  35. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  36. GRB 240805B: Swift-XRT refined Analysis
  37. GRB 240805B: Swift/UVOT Upper Limits
  38. GRB 240805A: Swift/UVOT Upper Limits
  39. GRB 240805A: SVOM/GRM observation
  40. GRB 240805B: Enhanced Swift-XRT position
  41. GRB 240805B: LCOGT Optical Upper Limits
  42. Swift GRB 240805B: Global MASTER-Net observations report
  43. GRB 240805B: JinShan optical upper limits
  44. Swift GRB 240805A: Global MASTER-Net observations report
  45. GRB 240805A: Swift-XRT refined Analysis
  46. GRB 240805B: Swift detection of a burst
  47. GRB 240805A: Fermi-LAT detection
  48. GRB 240805A: INTEGRAL spectral analysis
  49. GRB 240805A: A long GRB detected by INTEGRAL
  50. GRB 240805A: Swift detection of a burst
  51. GRB 240730A: Swift-BAT refined analysis
  52. GRB240730A: BOOTES-5/JGT early optical upper limit
  53. Swift GRB 240730A: Global MASTER-Net observations report
  54. GRB 240730A: Swift-XRT refined Analysis
  55. GRB 240715A: Swift-XRT afterglow detection
  56. GRB 240730A: KAIT Optical Upper Limit
  57. GRB 240730A: Swift/UVOT Upper Limits
  58. GRB 240730A: Enhanced Swift-XRT position
  59. GRB 240730A: Swift detection of a burst
  60. GRB 240727A: Swift-BAT refined analysis
  61. LIGO/Virgo/KAGRA S240615dg: GRAWITA wide-field optical observations
  62. GRB 240727A: observations of optical counterpart.
  63. GRB 240727B: Swift-XRT observations
  64. GRB 240727A: Swift/UVOT detection
  65. GRB 240727A: NOT optical observation
  66. GRB 240727A: JinShan optical upper limits
  67. GRB 240727A Bassano Bresciano Observatory upper limit
  68. GRB 240727A: Swift-XRT refined Analysis
  69. GRB 240727A: Enhanced Swift-XRT position
  70. GRB 240727B: Fermi GBM Observation
  71. Swift GRB240727.16: Global MASTER-Net observations report
  72. GRB 240727B: Swift ToO observations
  73. GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
  74. GRB240727A: Skynet Optical Afterglow Observations
  75. GRB 240727A: TRT optical afterglow detection
  76. GRB 240727A: KAIT Optical Afterglow Candidate
  77. GRB 240727A: Swift detection of a burst
  78. Swift Trigger 1244778 is not a GRB
  79. Swift GRB240725.11: Global MASTER-Net observations report
  80. GRB 240720A: Swift-BAT refined analysis
  81. LIGO/Virgo/KAGRA S240716b: Upper limits from Swift/BAT-GUANO
  82. LIGO/Virgo/KAGRA S240703ad: Upper limits from Swift/BAT-GUANO
  83. GRB 240720A: AstroSat CZTI detection
  84. GRB 240720A: Fermi GBM observation
  85. GRB 240720A: Swift detection of a burst
  86. Swift GRB240720.02: Global MASTER-Net observations report
  87. GRB 240718A: Fermi-LAT Detection
  88. GRB 240712A: Swift-BAT refined analysis
  89. GRB 240715A: Swift/UVOT observations of the XRT sources.
  90. GRB 240715A: Swift-XRT observations
  91. GRB240713A: Swift/UVOT Upper LImits
  92. EP240708a: X-ray follow-up observations with Swift/XRT
  93. GRB 240713A: Swift-XRT observations
  94. GRB 240715A: TRT optical upper limit on one Swift/XRT candidate
  95. GRB 240712A: Swift-XRT refined Analysis
  96. GRB 240715A: Swift ToO observations
  97. GRB 240712A ATCA radio observations
  98. IPN triangulation of GRB 240715A (short)
  99. GW s240422ed: Swift UVOT follow-up
  100. GRB 240712A: Swift/UVOT Upper Limits

Advanced

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