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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"

7293 results found.

  1. GRB 100901A: Faulkes Telescope North afterglow candidate
  2. GRB 100901A: Swift detection of a burst with an optical afterglow
  3. GRB 100823A: Candidate IR afterglow
  4. GRB 100823A: Swift detection of a burst
  5. GRB 100816A: Gemini-N spectroscopy
  6. GRB 100814A: Swift UVOT observations of the optical afterglow
  7. GRB 100814A: Swift detection of a burst with an optical afterglow
  8. GRB 100814A: ROTSE-III Detection of Optical Counterpart
  9. GRB 100807A: Swift detection of a burst
  10. GRB 100805A: ROTSE-III Optical detection
  11. Trigger 430975: Swift detection of a possible burst
  12. GRB 100805A: Further P60 Monitoring
  13. GRB 100805A: P60 Optical Afterglow Candidate
  14. GRB 100805A: Swift detection of a burst with an optical counterpart
  15. GRB 100713A: CrAO optical limits
  16. GRB 100802A: P60 Observations
  17. GRB 100802A: Liverpool Telescope observations
  18. GRB 100802A: Possible Swift/UVOT Detection of Optical Afterglow
  19. GRB 100802A: Swift detection of a burst
  20. GRB 100728A: GROND Detection of the NIR Afterglow Candidate
  21. GRB 100728B: Swift detection of a burst with an optical counterpart
  22. GRB 100728A: Swift detection of a burst
  23. GRB 100727A: Swift detection of a burst
  24. GRB 100725B: Swift detection of a burst
  25. GRB 100725A: Swift detection of a burst
  26. GRB 100724A: fading afterglow seen with GROND
  27. GRB 100724A, GROND detection of an afterglow candidate
  28. GRB 100724A: Swift detection of a burst
  29. GRB 100713A: further inspection of TNG images
  30. GRB100713A: Swift X-ray afterglow detection
  31. GRB 100628A: Keck/LRIS Spectroscopy of Host Galaxy Candidate
  32. GRB 100628A: Swift XRT/UVOT refined analysis
  33. GRB 100704A: Swift detection of a burst
  34. GRB 100628A: GROND optical/NIR observations of the host candidate
  35. GRB 100628A: Gemini North Observations
  36. GRB100625A: GROND confirmation of constant source
  37. GRB 100625A Gemini-South 2nd epoch imaging
  38. GRB 100628A: Swift detection of a short hard burst
  39. GRB 100625A: Swift/UVOT Upper Limits
  40. GRB 100625A: Gemini candidate afterglow
  41. GRB 100625A: Swift detection of a short hard burst
  42. GRB 100621A: Swift detection of a burst
  43. GRB 100619A: Swift detection of a burst
  44. GRB 100615A: GROND observations, upper limits
  45. GRB 100615A: Swift detection of a burst
  46. GRB 100614A: Swift detection of a burst
  47. GRB 100606A: Swift detection of a burst
  48. GRB 100526A: Gemini/NIRI infrared afterglow candidate
  49. GRB 100526B: Swift XRT/UVOT observations
  50. GRB 100526A: Swift detection of a burst
  51. GRB 100522A: GROND observations, upper limits
  52. GRB 100522A: Swift detection of a burst
  53. GRB 100518A: BOOTES-3 optical observations
  54. GRB 100518A: Faulkes Telescope North Afterglow Candidate
  55. GRB 100518A: Swift target of opportunity observation of the INTEGRAL burst
  56. GRB 100514A: optical afterglow confirmation
  57. GRB 100514A: Swift detection of a burst
  58. GRB 100513A: PAIRITEL continued observations and confirmation of fading
  59. GRB 100513A: SARA-N Upper Limit
  60. GRB 100513A: PAIRITEL NIR afterglow candidate
  61. GRB 100513A: Swift detection of a burst
  62. Swift-BAT trigger 421695 is likely not astrophysical
  63. Trigger 421695: Swift detection of a possible burst
  64. GRB 100508A: Swift detection of a burst
  65. GRB 100504A: Swift detection of a burst
  66. Trigger 421072: Possible Swift detection of a GRB or transient
  67. GRB 100424A: CrAO optical observations
  68. GRB 100424A: NIR Afterglow Confirmation
  69. GRB 100424A: Gemini/NIRI H-band observations
  70. GRB 100425A: GROND afterglow observation
  71. GRB 100424A: Gemini/NIRI Candidate Afterglow
  72. GRB 100425A: candidate optical afterglow from the VLT
  73. GRB 100425A: Swift detection of a burst
  74. GRB 100424A: Swift detection of a burst
  75. Trigger 420256: Swift detection of a possible GRB
  76. GRB 100420A: Swift detection of a burst
  77. GRB 100418A: Swift detection of a burst with a possible optical afterglow
  78. GRB 100414A: Gemini-N candidate and redshift
  79. GRB 100414A: Enhanced Swift-XRT position of candidate afterglow
  80. GRB 100414A: Palomar Transient Factory Observations
  81. GRB 100413A: Swift detection of a burst
  82. Spin down rate and inferred dipole magnetic field of the new soft gamma-ray repeater SGR 1833-0832
  83. GRB 100316A: R-band limit
  84. GRB 100331B: Swift/XRT possible afterglow candidate
  85. Fermi/GBM and Swift/BAT detection of a burst from SGR 1806-20
  86. GRB 100322B or possible Galactic transient detected in ground analysis of BAT data
  87. Possible pulsation period in SGR 1833-0832
  88. GRB 100319A: Swift detection of a burst; possible SGR
  89. GRB 100316D: Swift XRT enhanced position and further refined analysis
  90. GRB 100316C: GROND Detection of a Optical/NIR Afterglow Candidate
  91. GRB 100316D: GROND Detection of the Optical/NIR Afterglow Candidate
  92. GRB 100316A: TAROT Calern observatory optical observations
  93. GRB100316A: Swift/UVOT Upper Limits
  94. Trigger 416140 is almost certainly not a GRB
  95. GRB 100316D: Swift detection of a burst
  96. GRB 100316B: GROND Detection of the Optical/NIR Afterglow Candidate
  97. GRB 100316C: Swift detection of a burst
  98. GRB 100316B: Swift detection of a burst with optical counterpart
  99. GRB 100316 optical candidate from 1.23m CAHA telescope
  100. GRB 100316 optical candidate from 1.23m CAHA telescope

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