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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"

21263 results found.

  1. GRB060218: Refined photometric calibration of comparison stars
  2. GRB 060319: WHT K-band candidate afterglow
  3. GRB060319: Swift/UVOT upper limits
  4. GRB 060319 optical observations at TNG
  5. GRB060319 : Liverpool Telescope optical limit
  6. GRB060319 - SDSS Pre-burst Observations
  7. GRB060319: Swift/XRT position
  8. GRB060313: Radio Observations
  9. GRB 060313: early afterglow NIR upper limits with REM
  10. Konus-Wind observation of GRB 060313
  11. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  12. GRB 060313: Swift/UVOT Observations
  13. GRB 060313, SMARTS optical/IR observations
  14. GRB060313: optical and near infrared observations with REM
  15. GRB 060313: Swift-BAT detection of a bright short hard burst
  16. GRB060218: SARA Observations of SN2006aj
  17. GRB 060312: Swift XRT team refined analysis
  18. GRB060306: APO Ks-band Imaging Observations
  19. GRB 060312: ROTSE-III Optical Limits
  20. Bright short hard GRB 060303: IPN localization and Konus spectrum
  21. GRB 060306: MAGNUM observations
  22. GRB060218: analysis of the XMM-Newton observation
  23. Swift/UVOT observations of GRB060306
  24. GRB 060306: Swift-XRT team refined analysis
  25. GRB 060306: Swift detection of a bright burst
  26. GRB060218: Ep,i - Eiso correlation
  27. GRB060223b: optical limit
  28. GRB 060223b: Swift/UVOT Upper Limits
  29. GRB 060218/SN 2006aj: K-380 optical observations
  30. GRB 060218/SN 2006aj, SMARTS optical/IR observations
  31. GRB200618: optical polarimetry and photometry
  32. GRB 060223B: Swift XRT possible afterglow
  33. GRB 060218/SN 2006aj: REM optical and near-infrared observations
  34. GRB 060218 : Radio upper limits from GMRT
  35. GRB 060223A:Xinglong optical limits
  36. GRB 060223a: Swift/UVOT refined analysis
  37. GRB 060223B: Swift detection of a bright burst
  38. GRB 060218: rebrightening
  39. GRB 060219: Swift-BAT refined analysis
  40. GRB 060218: Decline in r-band flux
  41. GRB060219: SARA Observations
  42. GRB 060219: Swift/UVOT Upper Limits
  43. GRB 051221B: Swift-XRT Team Refined Analysis
  44. GRB060218: Radio Afterglow Discovery
  45. GRB060219: SDSS pre-burst observations
  46. GRB 060219: Swift-BAT detection of a weak burst
  47. Oddball GRB 060218, transient or GRB?
  48. Brightening of the Optical Counterpart of the Possible GRB 060218
  49. GRB 060218: Pre-burst detection of a possible host galaxy
  50. GRB 060218A: ROTSE-III Possible Optical Flare
  51. GRB 060211B: Swift/UVOT Upper Limits
  52. GRB060218 : SDSS pre-burst observations
  53. GRB 060218: Swift XRT Position
  54. GRB 060213: optical afterglow not confirmed
  55. Swift UVOT observations of GRB060213
  56. GRB060213: Swift XRT observations and possible afterglow candidate
  57. Konus-Wind observation of bright hard GRB 060213
  58. GRB 060213: IPN localization
  59. GRB060211B: REM optical and NIR observations
  60. GRB 060211A: Further refined analysis of the Swift burst
  61. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  62. GRB 060211b: P60 Observations
  63. GRB 060211B: Swift/BAT refined analysis
  64. GRB060210: Swift/UVOT Upper Limits
  65. GRB 060210: Optical Observations
  66. GRB 060211: ROTSE-III Optical Limits
  67. GRB 060211: Swift detection of a long burst
  68. GRB060210: Optical Observations
  69. GRB060210: Early Optical Observations
  70. GRB 060210: optical evolution
  71. GRB 060210: Swift detection of a burst
  72. GRB060210: Optical afterglow
  73. GRB 060209 : TAROT optical observation
  74. GRB 060203: Swift/UVOT upper limits
  75. GRB 060206: TTT Observations
  76. GRB 060121 : WIDGET Pre-trigger limit
  77. GRB060204a: Swift XRT Source is not GRB Afterglow
  78. Orphan GRB Afterglow candidate
  79. GRB 060206: IR Detection of the Afterglow
  80. GRB 060204A: ROSAT Pointing
  81. GRB 060206: Super-LOTIS observations
  82. GRB060204A: Swift/UVOT observations
  83. GRB060206: SDSS Pre-Burst Observations
  84. GRB 060206: High redshift burst
  85. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  86. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  87. GRB060206: Optical afterglow
  88. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  89. GRB060203: WHT Z-band observations
  90. BAT GRB 060204C is probably not a GRB
  91. GRB060204C: optical observation
  92. GRB 060204A: Swift XRT upper limit
  93. GRB 060204A: FRAM optical observations
  94. GRB060204B: Swift/UVOT refined analysis
  95. GRB 060204C: optical observations
  96. Swift XRT Observation of GRB 060204C
  97. GRB 060204B: Swift-BAT refined analysis
  98. GRB 060204B: ART early limit
  99. GRB 060204b: Keck/LRIS Afterglow Confirmation
  100. GRB 060204C: Liverpool Telescopes optical limit

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