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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. Retraction of orphan GRB afterglow candidate
  2. Orphan GRB Afterglow candidate
  3. GRB 060204A: ROSAT Pointing
  4. GRB060206: Liverpool Telescope observation
  5. GRB 060206: RAPTOR observations of afterglow candidate variability.
  6. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  7. GRB060206: Swift-BAT detection of a burst
  8. GRB 060204b: Keck/LRIS Afterglow Confirmation
  9. GRB 060204C: Liverpool Telescopes optical limit
  10. GRB 060204C: Swift-BAT detection of a burst
  11. GRB060204B: Faulkes OT candidate
  12. GRB 060204B: Swift detection of a burst
  13. GRB 060203: P60 Confirmation of Optical Afterglow
  14. Possible GRB 060203: candidate optical counterpart
  15. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  16. GRB 060202: Swift/UVOT upper limits
  17. GRB060202: Faulkes North observation
  18. GRB 060202: Swift detection of a burst
  19. GRB 051211A: MDM Observations
  20. GRB050121b: optical observation
  21. GRB 060124: Confirmation of the Afterglow
  22. GRB 060124: XRT position
  23. GRB 060124: Optical Afterglow Candidate from Tautenburg
  24. GRB 060124: Optical Observations at Tautenburg
  25. GRB060124:MASTER optical observation
  26. GRB 060121: Liverpool Telescopes optical limits
  27. GRB 060121: candidate optical counterpart
  28. GRB 060116: PROMPT Observations
  29. GRB 060117: FRAM refined analysis
  30. GRB 060117: FRAM optical afterglow candidate
  31. GRB 060117: nearby galaxy
  32. GRB 060116: VLT optical observations
  33. GRB 060116: IR Candidate Afterglow
  34. GRB060116: Faulkes North observation
  35. GRB 060116: Swift-BAT detection of a burst
  36. GRB 060115: OT photometry with MITSuME
  37. GRB 060115: Swift/UVOT upper limits
  38. GRB 060115: MITSuME optical afterglow candidate
  39. GRB 060115: Swift detection of a burst
  40. GRB060114: Faulkes North observation
  41. GRB060108: Faulkes North afterglow evidence
  42. GRB 060111A: refined UVOT anaysis
  43. GRB 060111B: MITSuME detection of optical afterglow
  44. GRB060111A: RTT150 optical observations
  45. GRB 060111B: Swift detection of a burst
  46. GRB060111.2:_MASTER optical limit
  47. GRB 060111: possible UVOT counterpart
  48. GRB 060111: Swift detection of a burst
  49. GRB 060110: Mitsume optical observations
  50. GRB 060110: IR Candidate Afterglow
  51. GRB 060110: Super-LOTIS observations
  52. GRB 060110: Optical observation
  53. GRB 060110: Correction
  54. GRB 060110: Optical limit
  55. GRB 060109: Swift Detection of a long burst
  56. GRB060108: Faulkes Telescope observation
  57. GRB060108: Swift detection of its 100th GRB
  58. GRB 060105: Swift/UVOT upper limits
  59. GRB 060102 - no XRT afterglow
  60. GRB060105 : Kiso optical observation
  61. GRB060105: Swift detection of a bright long burst
  62. Swift-BAT trigger 175653 is not an astrophysical source
  63. GRB051211B: optical observations
  64. GRB 051221B: Optical Observations with Kuiper 1.54m
  65. GRB 051227: optical observation
  66. GRB 051227: P60 Observations
  67. GRB 051227: R-band object in the XRT error circle
  68. GRB 051227: Swift detection of a burst
  69. GRB051117B: optical observation
  70. GRB 051221: Continued fading of optical afterglow
  71. GRB 051221A: RAPTOR Fading Counterpart Constraint
  72. Swift-BAT detection of a possible burst
  73. GRB 051221: Swift/UVOT upper limits
  74. GRB 051221: Swift detection of a bright short burst
  75. GRB051211A: possible optical candidate
  76. GRB 051215: A short GRB in a cluster?
  77. GRB 051211B: Swift XRT confirmation of the afterglow
  78. GRB051211B: Liverpool Telescope observation
  79. GRB 051211b: RTT150 optical observations
  80. GRB 051211B: Swift XRT Observations
  81. GRB 051211B: a possible optical detection by TAROT
  82. GRB051111: Rc optical observations
  83. GRB 051117B: Swift detection of a burst
  84. Faulkes Telescope R-band detection of GRB051111
  85. GRB 051109a: IR Detections
  86. GRB051103: MASTER: OT limit and host galaxy candidates
  87. GRB 051105A, 2nd epoch optical observations
  88. GRB051103:_MASTER_optical_observations
  89. GRB 051105: Optical limit
  90. GRB051016B: optical observation
  91. GRB051028: optical observations
  92. GRB051028: confirmation of the afterglow
  93. GRB051028: WHT optical candidate
  94. GRB051028:MASTER observations
  95. GRB051028:MASTER optical observations
  96. GRB 051022: XRT Refined Spectral and Temporal Analysis
  97. GRB051021A: Swift XRT refined analysis
  98. GRB051021b: Magellan IR Imaging
  99. GRB 051021, SMARTS optical/IR observations
  100. GRB 051021: Optical observations

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