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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"

12334 results found.

  1. GRB 090831B: Swift detection of a possible burst
  2. GRB 090827: Swift XRT and UVOT observations
  3. GRB 090823: Swift XRT possible detection of the X-ray afterglow
  4. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  5. GRB 090817: aphotometry of USNO-B1.0 341-0096763
  6. GRB 090817: Liverpool Telescope Observations
  7. GRB 090817: optical upper limit
  8. GRB 090815C: Swift refined analysis
  9. GRB 090817: Swift/UVOT Upper Limits
  10. GRB 090817: Swift-XRT observations
  11. GRB 090814B: I-band observations from 1.23m CAHA telescope
  12. GRB 090814B: Swift/UVOT Upper Limits
  13. GRB 090814B: Liverpool Telescope Observations
  14. GRB 090814A: Swift/UVOT Observations
  15. GRB 090814A, RIMOTS optical upper limits
  16. GRB 090813: correction to GCN 9787
  17. GRB090813: Swift/UVOT upper limits
  18. GRB 090813: Swift detection of a burst
  19. GRB 090812: WIRO NIR upper limit
  20. GRB 090812, RIMOTS optical upper limits
  21. GRB090812: Swift/UVOT observations
  22. GRB 090812: GROND Observations of the Optical/NIR Afterglow
  23. VLA radio upper limit on GRB 090809
  24. GRB 090621B: MAGIC telescope GeV observation
  25. GRB 090621A: MAGIC telescope GeV observation
  26. GRB090809: Swift/UVOT observations
  27. GRB 090807: MITSuME optical upper limit
  28. GRB 090807: Swift/UVOT Upper Limits
  29. GRB 090807, RIMOTS optical upper limits
  30. GRB 090807: Swift detection of a burst
  31. GRB 090727: GRT Optical Observation
  32. GRB 090726: GRT Optical Observation
  33. GRB 090727: Swift/UVOT Upper Limits
  34. GRB 090728: Swift/UVOT Upper Limits
  35. GRB 090728, RIMOTS optical upper limits
  36. GRB 090728: Swift detection of a burst
  37. GRB090726: Swift/UVOT observations
  38. Swift XRT and UVOT refned analysis of GRB 090720
  39. GRB 090715B: Swift/UVOT followup observations
  40. GRB 090709A: Xinglong TNT optical upper limit
  41. GRB 090621B: MTM-500 optical observations
  42. GRB 090709A: Swift UVOT upper limits
  43. GRB 090709A: evidence for a very red afterglow at low z
  44. GRB 090709A: P60 Observations
  45. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  46. GRB 090709A, RIMOTS optical upper limits
  47. GRB 090709: Faulkes Telescope North Upper Limits
  48. GRB 090709: PAIRITEL NIR Upper Limits
  49. Possible GRB090705: Swift-XRT observations
  50. GRB 090705: Swift detection of a possible burst
  51. XRF 090702 : RTT150 optical observations
  52. GRB 090529: CrAO optical upper limit
  53. GRB 090529: MTM-500 optical observations
  54. GRB 090702: UVOT upper limits
  55. GRB 090628: Swift/UVOT Upper Limits
  56. GRB 090628: GROND upper limits
  57. GRB 090628: Swift/UVOT Finding Chart Observation
  58. GRB 090625B: Swift/UVOT Upper Limits
  59. GRB 090625B: GROND upper limits
  60. GRB 090621B: GRT Optical Observation
  61. GRB 090621A: GRT Optical Observation
  62. GRB 090621B: Swift/UVOT Upper Limits
  63. GRB 090621: Swift/UVOT Upper Limits
  64. GRB 090621: Swift detection of a burst
  65. GRB090618: Swift/UVOT bright afterglow detection
  66. GRB 090618: AGILE observations
  67. GRB 090607: Swift/UVOT Upper Limits
  68. GRB 090607: GRAS001 optical observations
  69. GRB 090530: Further NOT optical observations
  70. GRB 090530: RTT150 Optical Observation
  71. GMRT observation of GRB 090424 afterglow
  72. GRB 090531B: GROND observation
  73. GRB090529B: ROVOR Upper Limits
  74. GRB 090531A: SARA upper limit
  75. Corrections to GRB 090531B Swift/UVOT Upper Limits
  76. GRB 090531B, RIMOTS optical upper limits
  77. GRB 090531B: Swift/UVOT Upper Limits
  78. GRB 090530: GRT Optical Observation
  79. Initial Swift/UVOT observations of GRB 090531B
  80. GRB 090531: GROND upper limits
  81. GRB090530: Swift XRT refined analysis
  82. GRB090530: Swift/UVOT afterglow detection
  83. GRB 090530: GRAS002 refined OA analysis
  84. GRB 090530: GRAS002 optical observations
  85. GRB090529: UVOT/Swift detection of a brightening optical afterglow
  86. GRB 090529: Preliminary Swift/UVOT Upper Limit
  87. GRB 090529: Swift detection of a burst
  88. GRB 090518 - NOT upper limit
  89. GRB 090520: GROND upper limits
  90. GRB 090519: Swift/UVOT Upper Limits
  91. GRB 090519: Swift detection of a burst
  92. GRB 090518: Swift/UVOT Upper Limits
  93. GRB090518: GROND upper limits
  94. GRB 090516, RIMOTS optical upper limits
  95. GRB090518 : Optical upper limit by MOA-II telescope
  96. GRB 090516: Swift/UVOT Observations
  97. GRB 090516: Swift detection of a burst
  98. GRB 090515: Lick Upper Limits
  99. GRB 090515: ROVOR Upper Limit
  100. GRB 090515: MMT/MMIRS NIR Upper Limit

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