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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"

19543 results found.

  1. SGR 1900+14: Swift detection of an outburst
  2. GRB 060413: Swift detection of a burst
  3. GRB 060403: MITSuME optical observation
  4. GRB060403: Optical Limit
  5. GRB 060403: Swift/UVOT upper limits
  6. SGR 1900+14: BAT observations
  7. GRB 060403: Refined analysis of the Swift-BAT burst
  8. GRB 060403: Swift detection of a burst
  9. HETE trigger H4044: RTT150 optical observations
  10. GRB060331: Swift/UVOT upper limits
  11. Swift XRT observations of the HETE transient H4043
  12. H4043, an unusual high-energy transient observed by HETE
  13. GRB 060322: LNA optical limit
  14. SGR 1900+14: Swift-BAT detection of a cluster of outbursts
  15. GRB 060323 : WIDGET simultaneous optical observations
  16. GRB 060323: Early optical observation at Xinglong
  17. GRB 060322: Confirmation of Swift XRT afterglow
  18. GRB060323: NOT optical observations
  19. GRB 060322: IAC80 optical observations
  20. GRB 060322: Swift XRT afterglow candidate
  21. GRB060323: P60 Observations
  22. GRB 060323: Swift/UVOT Observations
  23. GRB 060323: optical afterglow confirmed
  24. GRB060323: NOT observations
  25. GRB 060323: Optical Observations
  26. GRB 060323: optical observations at TNG
  27. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  28. GRB060323, optical observation
  29. GRB060323 - SDSS Pre-Burst Observations
  30. GRB 060323: Swift detection of a burst with a possible optical afterglow
  31. GRB 060322: Swift-BAT detection of a 200-sec burst
  32. GRB 060218/SN 2006aj, LNA optical observation
  33. GRB060218: Refined photometric calibration of comparison stars
  34. GRB 060319: WHT K-band candidate afterglow
  35. GRB060319: Swift/UVOT upper limits
  36. GRB060319: MASTER limit
  37. GRB 060319 optical observations at TNG
  38. GRB060319 : Liverpool Telescope optical limit
  39. GRB060319 - SDSS Pre-burst Observations
  40. GRB 060319: Swift detection of a burst
  41. GRB060313: Radio Observations
  42. GRB 060313: early afterglow NIR upper limits with REM
  43. GRB 060313: Swift/UVOT Observations
  44. GRB 060313: Swift XRT position
  45. GRB 060313, SMARTS optical/IR observations
  46. GRB060313: optical and near infrared observations with REM
  47. GRB 060313: Swift-BAT detection of a bright short hard burst
  48. GRB060218: SARA Observations of SN2006aj
  49. GRB 060312: Swift XRT team refined analysis
  50. GRB060306: APO Ks-band Imaging Observations
  51. GRB 060312: ROTSE-III Optical Limits
  52. Bright short hard GRB 060303: IPN localization and Konus spectrum
  53. GRB 060306: MAGNUM observations
  54. GRB060218: analysis of the XMM-Newton observation
  55. Swift/UVOT observations of GRB060306
  56. GRB 060306: Swift-XRT team refined analysis
  57. GRB 060306: Swift detection of a bright burst
  58. GRB060218: Ep,i - Eiso correlation
  59. GRB060223b: optical limit
  60. GRB 060223b: Swift/UVOT Upper Limits
  61. GRB 060218/SN 2006aj: K-380 optical observations
  62. GRB 060218/SN 2006aj, SMARTS optical/IR observations
  63. GRB 060223B: Swift XRT possible afterglow
  64. GRB 060218/SN 2006aj: REM optical and near-infrared observations
  65. GRB 060218 : Radio upper limits from GMRT
  66. GRB 060223A:Xinglong optical limits
  67. GRB 060223B: Swift-BAT refined analysis
  68. GRB 060223a: Swift/UVOT refined analysis
  69. GRB 060218/SN 2006aj: Swift-BAT fluence and peak flux
  70. GRB 060223B: Swift detection of a bright burst
  71. GRB 060218: rebrightening
  72. Spectral properties of GRB060218/SN2006aj
  73. GRB 060218: Decline in r-band flux
  74. GRB060219: SARA Observations
  75. GRB 060219: Swift/UVOT Upper Limits
  76. GRB 051221B: Swift-XRT Team Refined Analysis
  77. GRB060218: Radio Afterglow Discovery
  78. GRB060219: SDSS pre-burst observations
  79. GRB 060219: Swift-BAT detection of a weak burst
  80. Oddball GRB 060218, transient or GRB?
  81. GRB 060218: Pre-burst detection of a possible host galaxy
  82. Preliminary refined analysis of the Swift-BAT trigger 191157
  83. GRB 060211B: Swift/UVOT Upper Limits
  84. GRB060218 : SDSS pre-burst observations
  85. GRB 060213: optical afterglow not confirmed
  86. Swift UVOT observations of GRB060213
  87. GRB060213: Swift XRT observations and possible afterglow candidate
  88. GRB060206: Swift XRT observations of an unbroken powerlaw decay
  89. GRB 060213: IPN localization
  90. GRB060211B: REM optical and NIR observations
  91. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  92. GRB 060211b: P60 Observations
  93. GRB 050826: Optical Afterglow and Host Galaxy
  94. GRB060210: Swift/UVOT Upper Limits
  95. GRB 060210: Optical Observations
  96. GRB 060211B: Swift-BAT detection of a burst
  97. GRB 060211: Swift detection of a long burst
  98. GRB 060210: Swift detection of a burst
  99. GRB060210: Optical afterglow
  100. GRB 060209 : TAROT optical observation

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