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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"

8293 results found.

  1. GRB 060319: WHT K-band candidate afterglow
  2. GRB060319 : Liverpool Telescope optical limit
  3. GRB060319: MASTER optical observation
  4. GRB 060319: Swift detection of a burst
  5. GRB 060313: early afterglow NIR upper limits with REM
  6. GRB060313: SSO 40inch Observations
  7. GRB 060313: PROMPT Observations
  8. GRB060313:Gemini South Observations
  9. GRB060313: optical observations of the afterglow candidate
  10. GRB 060313: Swift-BAT detection of a bright short hard burst
  11. GRB060312: Swift UVOT observation
  12. GRB 060306: Swift-BAT refined analysis
  13. GRB 060306: Swift detection of a bright burst
  14. GRB 060223B: Swift XRT possible afterglow
  15. GRB 060218/SN 2006aj: ABT observations
  16. GRB 060218: rebrightening
  17. GRB 060223: Swift detection of a burst
  18. GRB 060218: spectroscopic observations
  19. GRB 060218: Likely an underluminous GRB
  20. GRB060218: Radio Afterglow Discovery
  21. GRB 060219: Swift-BAT detection of a weak burst
  22. Brightening of the Optical Counterpart of the Possible GRB 060218
  23. GRB 060218: MDM Observations
  24. GRB 060218: Pre-burst detection of a possible host galaxy
  25. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  26. GRB 060218: Swift-BAT detection of a possible burst
  27. GRB 060213: optical afterglow not confirmed
  28. Swift UVOT observations of GRB060213
  29. GRB 060213: optical afterglow candidate
  30. GRB060213: Swift XRT observations and possible afterglow candidate
  31. GRB060213: MASTER final result
  32. GRB060213:_MASTER_optical_observation
  33. GRB 050826: Optical Afterglow and Host Galaxy
  34. GRB 060210: Optical Observations
  35. GRB060211.7: MASTER_optical_observation under the snow
  36. GRB 060211B: Swift-BAT detection of a burst
  37. GRB 060211: Swift detection of a long burst
  38. GRB 060210: Refined analysis of the Swift-BAT burst
  39. GRB060210:Faulkes Telescope North Afterglow Confirmation
  40. GRB 060210: candidate afterglow
  41. GRB 060210: Swift detection of a burst
  42. GRB060210: Optical afterglow
  43. GRB060209A: MASTER optical observation
  44. GRB 060209(?): Swift-BAT detection of a possible burst
  45. GRB 060203: Swift/UVOT upper limits
  46. Retraction of orphan GRB afterglow candidate
  47. Orphan GRB Afterglow candidate
  48. GRB 060204A: ROSAT Pointing
  49. GRB060206: Liverpool Telescope observation
  50. GRB 060206: RAPTOR observations of afterglow candidate variability.
  51. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  52. GRB060206: Swift-BAT detection of a burst
  53. GRB 060204b: Keck/LRIS Afterglow Confirmation
  54. GRB 060204C: Liverpool Telescopes optical limit
  55. GRB 060204C: Swift-BAT detection of a burst
  56. GRB060204B: Faulkes OT candidate
  57. GRB 060204B: Swift detection of a burst
  58. GRB 060203: P60 Confirmation of Optical Afterglow
  59. Possible GRB 060203: candidate optical counterpart
  60. GRB 060202: Gemini-N J, H, K_s observations
  61. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  62. GRB 060202: Swift/UVOT upper limits
  63. GRB060202: Faulkes North observation
  64. GRB 060202: Swift detection of a burst
  65. GRB 060130: Swift/XRT observation
  66. GRB 051211A: MDM Observations
  67. GRB050121b: optical observation
  68. GRB 060124: Confirmation of the Afterglow
  69. GRB 060124: XRT position
  70. GRB 060124: Optical Afterglow Candidate from Tautenburg
  71. GRB 060124: Optical Observations at Tautenburg
  72. GRB060124:MASTER optical observation
  73. GRB 060121: Liverpool Telescopes optical limits
  74. GRB 060121: candidate optical counterpart
  75. GRB060121: SARA Observations
  76. GRB060117 - ATCA 3/6cm radio limits - correction
  77. GRB060117 - ATCA 3/6cm radio limits
  78. GRB 060116: photometric redshift - the farthest GRB?
  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. GRB 060108: IR observations of afterglow
  93. GRB060108: Faulkes North afterglow evidence
  94. GRB 060111A: refined UVOT anaysis
  95. GRB 060111B: MITSuME detection of optical afterglow
  96. GRB060111A: RTT150 optical observations
  97. GRB 060111B: Swift detection of a burst
  98. GRB060111.2:_MASTER optical limit
  99. GRB 060111: possible UVOT counterpart
  100. GRB 060111: Swift detection of a burst

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