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"

28053 results found.

  1. GRB060108: SDSS pre-burst observations
  2. GRB060108: Faulkes Telescope observation
  3. GRB060108, optical observation
  4. GRB 060108: Refined analysis of the Swift-BAT burst
  5. GRB060108: Swift detection of its 100th GRB
  6. GRB 060105: ISAS observations and near IR upper limit
  7. GRB 060105: Swift/UVOT upper limits
  8. GRB 060105: Mitsume optical observations
  9. GRB 060105: BAT refined analysis
  10. GRB 060105: XRT refined analysis
  11. GRB060105: Suzaku-XIS and -HXD observation plan
  12. GRB060105, optical observation
  13. GRB060105: Swift detection of a bright long burst
  14. Swift-BAT trigger 175653 is probably not a GRB
  15. GRB 060102: Swift-BAT refined analysis
  16. GRB 060102: Swift-BAT detection of a burst
  17. GRB 051221B: Optical Observations with Kuiper 1.54m
  18. GRB 051227: Likely host galaxy underlying afterglow position
  19. GRB 051227: optical observation
  20. GRB 051227: optical afterglow
  21. GRB 051227: Magellan r'-band Imaging/Astrometry
  22. GRB 051227: refined analysis of VLT images
  23. GRB 051227: P60 Observations
  24. GRB 051227: MDM Observation
  25. GRB 051227: R-band object in the XRT error circle
  26. GRB 051227: XRT refined analysis
  27. GRB 051227: Further analysis of the Swift-BAT burst
  28. GRB 051227: Refined analysis of the Swift-BAT burst
  29. GRB051227: SDSS pre-burst observations
  30. GRB 051227, optical observation
  31. GRB051117B: optical observation
  32. Konus-Wind observation of GRB 051221A
  33. GRB051221A: Suzaku WAM observation of the prompt emission
  34. GRB 051221A: MDM Optical Observations
  35. GRB051016: analysis of the XMM-Newton observation
  36. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  37. GRB 051221B: TAROT optical limits
  38. GRB 051221B: Refined analysis of the Swift-BAT burst
  39. GRB 051221B: BOOTES optical observations.
  40. Swift-BAT detection of a possible burst
  41. GRB 051221: Swift XRT refined analysis
  42. GRB 051221: Swift/UVOT upper limits
  43. GRB 051221: No variability in Gemini data
  44. GRB 051221: Improved astrometry of the IR counterpart
  45. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  46. GRB 051221: Swift detection of a bright short burst
  47. Swift detection of an RS CVn flare star
  48. GRB051211A: possible optical candidate
  49. GRB 051215: near-infrared observations
  50. GRB051215 - SDSS pre-burst observations
  51. GRB 051215: Swift detection of a possible burst
  52. GRB051105: optical observations
  53. GRB 051213: Swift-BAT refined analysis
  54. GRB051211B: XRT refined analysis
  55. GRB 051211B, optical observation
  56. GRB 051211A: Swift/UVOT upper limits
  57. GRB 051211B: Swift/UVOT upper limits
  58. GRB 051211A,optical observation
  59. GRB051211B: Liverpool Telescope observation
  60. GRB051211b: P60 Observations
  61. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  62. GRB 051210: Swift/UVOT upper limits
  63. GRB 051210: Magellan Imaging
  64. GRB 051211: TAROT optical limits
  65. GRB 051211B: a possible optical detection by TAROT
  66. GRB 051211:IAC80 optical observations
  67. GRB 051210: SALT detection limit
  68. GRB 051210: Swift XRT refined analysis
  69. GRB 051210: FRAM early limit
  70. GRB 051210: Swift-BAT refined analysis of a short burst
  71. GRB051210: Swift UVOT Observation
  72. GRB 051210: Swift detection of a burst
  73. An extraordinary long burst on December 3 from SGR1806-20
  74. Possible resuming of the SGR 1806-20 activity
  75. GRB051117B: Swift XRT refined analysis
  76. GRB051117b: No Swift/UVOT Detection
  77. GRB 051117A: Swift/UVOT Detection of an Afterglow: Correction
  78. GRB 051117A: Swift/UVOT Detection of an Afterglow
  79. GRB051111: Suzaku WAM observation of the prompt emission
  80. GRB051008: Suzaku WAM observation of the prompt emission
  81. GRB 051117B: R and I observations of possible host galaxy
  82. GRB 051117A: Refined analysis of the Swift-BAT burst
  83. GRB 051117B: Refined analysis of the Swift-BAT burst
  84. GRB 051117B,optical observation
  85. GRB 051117B: Lulin R and I band observation
  86. GRB051114: results of the Swift-XRT observation
  87. GRB 051109B : Nainital upper limits
  88. GRB 051114: Radio Observations
  89. GRB 051114: Swift-BAT refined analysis
  90. GRB050925: analysis of the XMM-Newton observation
  91. GRB 051114: Swift-BAT detection of a short burst
  92. GRB 051111: Further spectroscopic analysis
  93. GRB 051111: Radio afterglow
  94. GRB 051113: Swift-BAT refined analysis
  95. GRB051103: Radio Observations
  96. GRB/SGR 050925: XMM-Newton ToO observation
  97. GRB051111: Swift/UVOT Observations
  98. GRB051111: XRT preliminary analysis
  99. GRB 051111: Swift-BAT refined analysis
  100. GRB 051109A Optical Observations

Advanced

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