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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"

7407 results found.

  1. GRB 100925A: Swift detection of a burst
  2. GRB 100915A: Swift detection of a likely burst
  3. Swift BAT Trigger 433953 probably not a GRB
  4. GRB 100909A: Faulkes Telescope North afterglow candidate
  5. GRB 100902A : Confirmation of afterglow and re-brightening with CFHT r’-band imaging
  6. GRB 100909A: Swift target of opportunity observation
  7. GRB 100906A : Faulkes Telescope North optical observations
  8. GRB 100906A: Swift detection of a burst with an optical afterglow
  9. GRB 100905A: Swift detection of a burst
  10. GRB 100902A: UKIRT JK Observation
  11. GRB 100902A: GROND observations; afterglow candidate
  12. GRB 100902A: Swift detection of a burst
  13. GRB 100901A: ROTSE-III Detection
  14. GRB 100901A: confirmation of the afterglow
  15. GRB 100901A: Faulkes Telescope North afterglow candidate
  16. GRB 100901A: Swift detection of a burst with an optical afterglow
  17. GRB 100823A: Candidate IR afterglow
  18. GRB 100823A: Swift detection of a burst
  19. GRB 100816A: Gemini-N spectroscopy
  20. GRB 100814A: Swift UVOT observations of the optical afterglow
  21. GRB 100814A: Swift detection of a burst with an optical afterglow
  22. GRB 100814A: ROTSE-III Detection of Optical Counterpart
  23. GRB 100807A: Swift detection of a burst
  24. GRB 100805A: ROTSE-III Optical detection
  25. Trigger 430975: Swift detection of a possible burst
  26. GRB 100805A: Further P60 Monitoring
  27. GRB 100805A: P60 Optical Afterglow Candidate
  28. GRB 100805A: Swift detection of a burst with an optical counterpart
  29. GRB 100713A: CrAO optical limits
  30. GRB 100802A: P60 Observations
  31. GRB 100802A: Liverpool Telescope observations
  32. GRB 100802A: Possible Swift/UVOT Detection of Optical Afterglow
  33. GRB 100802A: Swift detection of a burst
  34. GRB 100728A: GROND Detection of the NIR Afterglow Candidate
  35. GRB 100728B: Swift detection of a burst with an optical counterpart
  36. GRB 100728A: Swift detection of a burst
  37. GRB 100727A: Swift detection of a burst
  38. GRB 100725B: Swift detection of a burst
  39. GRB 100725A: Swift detection of a burst
  40. GRB 100724A: fading afterglow seen with GROND
  41. GRB 100724A, GROND detection of an afterglow candidate
  42. GRB 100724A: Swift detection of a burst
  43. GRB 100713A: further inspection of TNG images
  44. GRB100713A: Swift X-ray afterglow detection
  45. GRB 100628A: Keck/LRIS Spectroscopy of Host Galaxy Candidate
  46. GRB 100628A: Swift XRT/UVOT refined analysis
  47. GRB 100704A: Swift detection of a burst
  48. GRB 100628A: GROND optical/NIR observations of the host candidate
  49. GRB 100628A: Gemini North Observations
  50. GRB100625A: GROND confirmation of constant source
  51. GRB 100625A Gemini-South 2nd epoch imaging
  52. GRB 100628A: Swift detection of a short hard burst
  53. GRB 100625A: Swift/UVOT Upper Limits
  54. GRB 100625A: Gemini candidate afterglow
  55. GRB 100625A: Swift detection of a short hard burst
  56. GRB 100621A: Swift detection of a burst
  57. GRB 100619A: Swift detection of a burst
  58. GRB 100615A: GROND observations, upper limits
  59. GRB 100615A: Swift detection of a burst
  60. GRB 100614A: Swift detection of a burst
  61. GRB 100606A: Swift detection of a burst
  62. GRB 100526A: Gemini/NIRI infrared afterglow candidate
  63. GRB 100526B: Swift XRT/UVOT observations
  64. GRB 100526A: Swift detection of a burst
  65. GRB 100522A: GROND observations, upper limits
  66. GRB 100522A: Swift detection of a burst
  67. GRB 100518A: BOOTES-3 optical observations
  68. GRB 100518A: Faulkes Telescope North Afterglow Candidate
  69. GRB 100518A: Swift target of opportunity observation of the INTEGRAL burst
  70. GRB 100514A: optical afterglow confirmation
  71. GRB 100514A: Swift detection of a burst
  72. GRB 100513A: PAIRITEL continued observations and confirmation of fading
  73. GRB 100513A: SARA-N Upper Limit
  74. GRB 100513A: PAIRITEL NIR afterglow candidate
  75. GRB 100513A: Swift detection of a burst
  76. Swift-BAT trigger 421695 is likely not astrophysical
  77. Trigger 421695: Swift detection of a possible burst
  78. GRB 100508A: Swift detection of a burst
  79. GRB 100504A: Swift detection of a burst
  80. Trigger 421072: Possible Swift detection of a GRB or transient
  81. GRB 100424A: CrAO optical observations
  82. GRB 100424A: NIR Afterglow Confirmation
  83. GRB 100424A: Gemini/NIRI H-band observations
  84. GRB 100425A: GROND afterglow observation
  85. GRB 100424A: Gemini/NIRI Candidate Afterglow
  86. GRB 100425A: candidate optical afterglow from the VLT
  87. GRB 100425A: Swift detection of a burst
  88. GRB 100424A: Swift detection of a burst
  89. Trigger 420256: Swift detection of a possible GRB
  90. GRB 100420A: Swift detection of a burst
  91. GRB 100418A: Swift detection of a burst with a possible optical afterglow
  92. GRB 100414A: Gemini-N candidate and redshift
  93. GRB 100414A: Enhanced Swift-XRT position of candidate afterglow
  94. GRB 100414A: Palomar Transient Factory Observations
  95. GRB 100413A: Swift detection of a burst
  96. Spin down rate and inferred dipole magnetic field of the new soft gamma-ray repeater SGR 1833-0832
  97. GRB 100316A: R-band limit
  98. GRB 100331B: Swift/XRT possible afterglow candidate
  99. Fermi/GBM and Swift/BAT detection of a burst from SGR 1806-20
  100. GRB 100322B or possible Galactic transient detected in ground analysis of BAT data

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