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"

26536 results found.

  1. GRB 060108: ISAS early observations and near IR upper limit
  2. GRB060108: P200 Ks Observations
  3. GRB 060108: early UKIRT K-band observations
  4. GRB 060108: Refined XRT analysis
  5. GRB 060108: VLT J-band observations
  6. GRB 060108: Mitsume optical observations
  7. GRB 060108: Swift/UVOT upper limits
  8. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  9. GRB060108: SDSS pre-burst observations
  10. GRB060108: Faulkes Telescope observation
  11. GRB060108, optical observation
  12. GRB060108: Swift detection of its 100th GRB
  13. Konus-Wind observation of GRB 060105
  14. GRB 060105: ISAS observations and near IR upper limit
  15. GRB 060105: Swift/UVOT upper limits
  16. GRB 060105: Mitsume optical observations
  17. GRB 060102 - no XRT afterglow
  18. GRB 060105: XRT refined analysis
  19. GRB060105: Suzaku-XIS and -HXD observation plan
  20. GRB060105, optical observation
  21. GRB060105: Swift detection of a bright long burst
  22. Swift-BAT trigger 175653 is probably not a GRB
  23. GRB 060102: Swift-BAT refined analysis
  24. Time Correction to GRB 060102
  25. GRB 051221B: Optical Observations with Kuiper 1.54m
  26. GRB 051227: Likely host galaxy underlying afterglow position
  27. GRB 051227: optical observation
  28. GRB 051227: optical afterglow
  29. GRB 051227: Magellan r'-band Imaging/Astrometry
  30. GRB 051227: refined analysis of VLT images
  31. GRB 051227: P60 Observations
  32. GRB 051227: MDM Observation
  33. GRB 051227: R-band object in the XRT error circle
  34. GRB 051227: Joint Swift-HETE Spectral Analysis
  35. GRB 051227: XRT refined analysis
  36. GRB 051227: Further analysis of the Swift-BAT burst
  37. GRB 051227: Refined analysis of the Swift-BAT burst
  38. GRB051227: SDSS pre-burst observations
  39. GRB 051227, optical observation
  40. GRB051117B: optical observation
  41. Konus-Wind observation of GRB 051221A
  42. GRB 051221A: MDM Optical Observations
  43. GRB051016: analysis of the XMM-Newton observation
  44. GRB 051221B: TAROT optical limits
  45. GRB 051221B: Refined analysis of the Swift-BAT burst
  46. Swift-BAT detection of a possible burst
  47. GRB 051221: Swift XRT refined analysis
  48. GRB 051221: Swift/UVOT upper limits
  49. GRB 051221: Improved astrometry of the IR counterpart
  50. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  51. GRB 051221: IR Observations at GRB+1hr
  52. GRB 051221: Swift detection of a bright short burst
  53. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  54. GRB051211A (=H3979): Refined Analysis
  55. GRB 051211B: optical afterglow
  56. Swift detection of an RS CVn flare star
  57. GRB051211A: possible optical candidate
  58. GRB 051215: near-infrared observations
  59. GRB051215 - SDSS pre-burst observations
  60. GRB 051215: Swift detection of a possible burst
  61. GRB051211B: XRT refined analysis
  62. GRB 051211B, optical observation
  63. GRB 051211A: Swift/UVOT upper limits
  64. GRB 051211B: Swift/UVOT upper limits
  65. GRB 051211A,optical observation
  66. GRB 051211B: Swift XRT confirmation of the afterglow
  67. GRB051211B: Liverpool Telescope observation
  68. GRB051211b: P60 Observations
  69. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  70. GRB 051211B: Swift XRT Observations
  71. GRB 051210: Swift/UVOT upper limits
  72. GRB 051210: Magellan Imaging
  73. GRB 051211: TAROT optical limits
  74. GRB 051211B: a possible optical detection by TAROT
  75. GRB 051211:IAC80 optical observations
  76. GRB 051210: SALT detection limit
  77. GRB 051210: Swift XRT refined analysis
  78. GRB 051210: FRAM early limit
  79. GRB051210: Swift UVOT Observation
  80. GRB 051210: Swift detection of a burst
  81. Swift XRT positions
  82. An extraordinary long burst on December 3 from SGR1806-20
  83. GRB 051127: Swift-BAT detection of a possible burst
  84. GRB051117B: Swift XRT refined analysis
  85. GRB051117b: No Swift/UVOT Detection
  86. GRB 051117A: Swift/UVOT Detection of an Afterglow
  87. GRB051008: Suzaku WAM observation of the prompt emission
  88. GRB 051021 Optical Observations
  89. GRB 051117B: R and I observations of possible host galaxy
  90. GRB 051117A: Refined analysis of the Swift-BAT burst
  91. GRB 051117B: Refined analysis of the Swift-BAT burst
  92. GRB051117A : XRT refined analysis
  93. GRB 051117B,optical observation
  94. GRB 051117B: Swift detection of a burst
  95. GRB 051117: Swift detection of a bright burst
  96. GRB051114: results of the Swift-XRT observation
  97. GRB 051028 Optical Observations
  98. GRB 051109B : Nainital upper limits
  99. GRB 051114: Radio Observations
  100. GRB 051114: Swift-BAT refined analysis

Advanced

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