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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"

18732 results found.

  1. GRB 060313: Swift-BAT detection of a bright short hard burst
  2. GRB060312: Swift UVOT observation
  3. GRB 060312: Refined analysis of the Swift-BAT burst
  4. GRB 060312: Swift XRT team refined analysis
  5. GRB060306: APO Ks-band Imaging Observations
  6. GRB 060312: ROTSE-III Optical Limits
  7. GRB 060312: Swift detection of a burst
  8. Bright short hard GRB 060303: IPN localization and Konus spectrum
  9. GRB060218: analysis of the XMM-Newton observation
  10. Swift/UVOT observations of GRB060306
  11. GRB 060306: Swift-BAT refined analysis
  12. GRB 060306: Swift-XRT team refined analysis
  13. GRB 060306: Swift detection of a bright burst
  14. GRB060218: Ep,i - Eiso correlation
  15. GRB 060223b: Swift/UVOT Upper Limits
  16. GRB 060223B: Swift XRT possible afterglow
  17. GRB 060223B: Swift-BAT refined analysis
  18. GRB 060223a: Swift/UVOT refined analysis
  19. GRB 060223: Swift XRT Team preliminary analysis
  20. GRB 060218/SN 2006aj: Swift-BAT fluence and peak flux
  21. GRB 060223B: Swift detection of a bright burst
  22. GRB 060223: Swift-BAT refined analysis
  23. GRB 060218: rebrightening
  24. GRB 060223: Swift/UVOT Confirmation of Optical Afterglow
  25. GRB 060223: Swift detection of a burst
  26. GRB 060219: Swift-BAT refined analysis
  27. GRB 060218: Further refined analysis of the Swift-BAT burst
  28. GRB 060218: Likely an underluminous GRB
  29. GRB 060219: SDSS galaxy inside XRT error circle
  30. GRB060218: UV Detection and Light Curves
  31. GRB 060219: Swift/UVOT Upper Limits
  32. GRB 060219: Swift-XRT Team refined analysis
  33. GRB 051221B: Swift-XRT Team Refined Analysis
  34. GRB 060219: Partial refined analysis of the Swift-BAT burst
  35. GRB 060219: Swift-XRT position typo correction
  36. GRB 060219: Swift-XRT position
  37. GRB 060218: optical/nIR observations at La Palma
  38. GRB 060219: Swift-BAT detection of a weak burst
  39. Oddball GRB 060218, transient or GRB?
  40. GRB060218: Swift/XRT Team preliminary analysis of the possible burst
  41. Brightening of the Optical Counterpart of the Possible GRB 060218
  42. GRB 060218: MDM Observations
  43. GRB 060218A: ROTSE-III Possible Optical Flare
  44. GRB060218: Swift/XRT refined position of a possible burst
  45. Preliminary refined analysis of the Swift-BAT trigger 191157
  46. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  47. GRB 060211B: Swift/UVOT Upper Limits
  48. GRB 060218: Swift XRT Position
  49. GRB 060218: Swift-BAT detection of a possible burst
  50. GRB 060213: optical afterglow not confirmed
  51. Swift UVOT observations of GRB060213
  52. GRB060213: Swift XRT observations and possible afterglow candidate
  53. GRB 060211b: WIRO NIR Observations
  54. GRB060206: Swift XRT observations of an unbroken powerlaw decay
  55. GRB 060213: IPN localization
  56. GRB 060211a: WIRO NIR Observations
  57. GRB 060211B: BAT detects no additional burst emission beyond T + 122 sec
  58. GRB 060211A: Further refined analysis of the Swift burst
  59. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  60. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  61. GRB 050826: Optical Afterglow and Host Galaxy
  62. GRB 060210: Further refined analysis of the Swift-BAT burst
  63. GRB 060211B: Swift/BAT refined analysis
  64. GRB060210: Swift/UVOT Upper Limits
  65. GRB 060211B: Swift-XRT Team refined analysis
  66. GRB060211B: Swift/XRT position
  67. GRB 060210: Optical Observations
  68. GRB 060211A: Swift XRT Team Refined Analysis
  69. GRB 060211B: Swift-BAT detection of a burst
  70. GRB060211: Faulkes North observation
  71. GRB 060211: Swift detection of a long burst
  72. GRB 060210: Refined analysis of the Swift-BAT burst
  73. GRB060210: Swift XRT Refined Analysis
  74. GRB060210: Early Optical Observations
  75. GRB060210:Faulkes Telescope North Afterglow Confirmation
  76. GRB 060210: candidate afterglow
  77. GRB 060210: Swift detection of a burst
  78. GRB060210: Optical afterglow
  79. GRB 060206: Swift/UVOT Observations
  80. Swift-BAT trigger 180931 is not a GRB
  81. GRB060209: RTT150 optical observations
  82. GRB 060209 : TAROT optical observation
  83. GRB 060209(?): Swift-BAT detection of a possible burst
  84. GRB 060206: WSRT Radio Observations
  85. GRB 060203: Swift/UVOT upper limits
  86. GRB060204a: Swift XRT Source is not GRB Afterglow
  87. GRB 060204b: pseudo-z from spectral parameters of the prompt emission
  88. GRB 060204A: ROSAT Pointing
  89. GRB060204A: Swift/UVOT observations
  90. GRB 060206: Swift-BAT refined analysis
  91. GRB060206: Swift XRT Refined Analysis
  92. GRB060206: Swift XRT Position
  93. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  94. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  95. GRB060206: Swift-BAT detection of a burst
  96. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  97. BAT GRB 060204C is probably not a GRB
  98. GRB 060204B: BVRi-band detections of optical afterglow
  99. GRB 060204A: Swift XRT upper limit
  100. GRB060204B: Swift/UVOT refined analysis

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