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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"

7444 results found.

  1. SGR 1900+14: Swift detection of an outburst
  2. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  3. GRB 060403: Swift detection of a burst
  4. H4043, an unusual high-energy transient observed by HETE
  5. GRB 060322: Confirmation of Swift XRT afterglow
  6. GRB060323: NOT optical observations
  7. GRB 060322: Swift XRT afterglow candidate
  8. GRB 060323: optical afterglow confirmed
  9. GRB 060323: Optical Observations
  10. GRB 060323: Tautenburg OT candidate retraction
  11. GRB 060323: optical observations at TNG
  12. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  13. GRB 060323: Swift/XRT position
  14. GRB 060319: WHT K-band candidate afterglow
  15. GRB060319 : Liverpool Telescope optical limit
  16. GRB060319: MASTER optical observation
  17. GRB 060319: Swift detection of a burst
  18. GRB 060313: early afterglow NIR upper limits with REM
  19. GRB060313: SSO 40inch Observations
  20. GRB 060313: PROMPT Observations
  21. GRB060313:Gemini South Observations
  22. GRB060313: optical observations of the afterglow candidate
  23. GRB 060313: Swift-BAT detection of a bright short hard burst
  24. GRB060312: Swift UVOT observation
  25. GRB 060306: Swift detection of a bright burst
  26. GRB 060223B: Swift XRT possible afterglow
  27. GRB 060223: Swift detection of a burst
  28. GRB060218: Radio Afterglow Discovery
  29. GRB 060219: Swift-BAT detection of a weak burst
  30. Brightening of the Optical Counterpart of the Possible GRB 060218
  31. GRB 060218: MDM Observations
  32. GRB 060218: Pre-burst detection of a possible host galaxy
  33. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  34. GRB 060218: Swift-BAT detection of a possible burst
  35. GRB 060213: optical afterglow not confirmed
  36. Swift UVOT observations of GRB060213
  37. GRB 060213: optical afterglow candidate
  38. GRB060213: Swift XRT observations and possible afterglow candidate
  39. GRB060213: MASTER final result
  40. GRB060213:_MASTER_optical_observation
  41. GRB 050826: Optical Afterglow and Host Galaxy
  42. GRB 060210: Optical Observations
  43. GRB060211.7: MASTER_optical_observation under the snow
  44. GRB 060211B: Swift-BAT detection of a burst
  45. GRB 060211: Swift detection of a long burst
  46. GRB060210:Faulkes Telescope North Afterglow Confirmation
  47. GRB 060210: candidate afterglow
  48. GRB 060210: Swift detection of a burst
  49. GRB060209A: MASTER optical observation
  50. GRB 060209(?): Swift-BAT detection of a possible burst
  51. GRB 060203: Swift/UVOT upper limits
  52. Retraction of orphan GRB afterglow candidate
  53. Orphan GRB Afterglow candidate
  54. GRB 060204A: ROSAT Pointing
  55. GRB060206: Liverpool Telescope observation
  56. GRB 060206: RAPTOR observations of afterglow candidate variability.
  57. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  58. GRB060206: Swift-BAT detection of a burst
  59. GRB 060204b: Keck/LRIS Afterglow Confirmation
  60. GRB 060204C: Liverpool Telescopes optical limit
  61. GRB 060204C: Swift-BAT detection of a burst
  62. GRB060204B: Faulkes OT candidate
  63. GRB 060204B: Swift detection of a burst
  64. GRB 060203: P60 Confirmation of Optical Afterglow
  65. Possible GRB 060203: candidate optical counterpart
  66. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  67. GRB 060202: Swift/UVOT upper limits
  68. GRB060202: Faulkes North observation
  69. GRB 060202: Swift detection of a burst
  70. GRB 051211A: MDM Observations
  71. GRB050121b: optical observation
  72. GRB 060124: Confirmation of the Afterglow
  73. GRB 060124: XRT position
  74. GRB 060124: Optical Afterglow Candidate from Tautenburg
  75. GRB 060124: Optical Observations at Tautenburg
  76. GRB060124:MASTER optical observation
  77. GRB 060121: Liverpool Telescopes optical limits
  78. GRB 060121: candidate optical counterpart
  79. GRB 060116: PROMPT Observations
  80. GRB 060117: FRAM refined analysis
  81. GRB 060117: FRAM optical afterglow candidate
  82. GRB 060117: nearby galaxy
  83. GRB 060116: VLT optical observations
  84. GRB 060116: IR Candidate Afterglow
  85. GRB060116: Faulkes North observation
  86. GRB 060116: Swift-BAT detection of a burst
  87. GRB 060115: OT photometry with MITSuME
  88. GRB 060115: Swift/UVOT upper limits
  89. GRB 060115: MITSuME optical afterglow candidate
  90. GRB 060115: Swift detection of a burst
  91. GRB060114: Faulkes North observation
  92. GRB060108: Faulkes North afterglow evidence
  93. GRB 060111A: refined UVOT anaysis
  94. GRB 060111B: MITSuME detection of optical afterglow
  95. GRB060111A: RTT150 optical observations
  96. GRB 060111B: Swift detection of a burst
  97. GRB060111.2:_MASTER optical limit
  98. GRB 060111: possible UVOT counterpart
  99. GRB 060111: Swift detection of a burst
  100. GRB 060110: Mitsume optical observations

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