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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"

18652 results found.

  1. GRB060418: Swift XRT Team Refined Analysis
  2. GRB060418: Magellan/MIKE Spectroscopic Redshift
  3. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  4. SGR 1900+14: Refined analysis of the Swift-BAT outburst
  5. GRB060413: Swift/UVOT upper limits
  6. SGR 1900+14: Swift detection of an outburst
  7. GRB 060413: Refined analysis of the Swift-BAT burst
  8. GRB 060413: XRT refined analysis
  9. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  10. GRB 060413: Swift detection of a burst
  11. GRB060403: XRT refined analysis
  12. GRB 060403: Swift/UVOT upper limits
  13. SGR 1900+14: BAT observations
  14. GRB 060403: Refined analysis of the Swift-BAT burst
  15. GRB060403: Swift XRT refined position
  16. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  17. GRB 060403: Swift detection of a burst
  18. GRB060331: Swift/UVOT upper limits
  19. Swift XRT observations of the HETE transient H4043
  20. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  21. SGR 1900+14: Swift-BAT detection of a cluster of outbursts
  22. SGR 1900+14: Swift-BAT detection of a bright outburst
  23. GRB 060323 : WIDGET simultaneous optical observations
  24. GRB 060322: Confirmation of Swift XRT afterglow
  25. GRB060323: optical limit
  26. SGR 1900+14: CORRECTION to GCN 4923
  27. SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
  28. SGR 1900+14: Swift detection of renewed activity
  29. GRB060323: NOT optical observations
  30. GRB 060322: IAC80 optical observations
  31. GRB 060322: Swift XRT afterglow candidate
  32. GRB 060323: Swift/UVOT Observations
  33. GRB060323: NOT observations
  34. GRB 060323: Refined analysis of the Swift-BAT burst
  35. GRB 060323: Swift XRT refined analysis
  36. GRB 060323: Swift/XRT position
  37. GRB 060322: Refined analysis of the Swift-BAT burst
  38. GRB060323 - SDSS Pre-Burst Observations
  39. GRB 060323: Swift detection of a burst with a possible optical afterglow
  40. GRB 060322: Swift-BAT detection of a 200-sec burst
  41. GRB 060319: IAC-80 optical observations
  42. GRB060319: Swift XRT refined analysis
  43. GRB060319: Swift/UVOT upper limits
  44. GRB 060319: Swift-BAT refined analysis
  45. GRB060319: Swift/XRT position
  46. GRB 060319: Swift detection of a burst
  47. Konus-Wind observation of GRB 060313
  48. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  49. GRB 060313: Swift/UVOT Observations
  50. GRB 060313: Swift-XRT team refined analysis
  51. GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
  52. GRB 060313: Swift XRT position
  53. GRB060313: optical and near infrared observations with REM
  54. GRB 060313: Swift-BAT detection of a bright short hard burst
  55. GRB060312: Swift UVOT observation
  56. GRB 060312: Refined analysis of the Swift-BAT burst
  57. GRB 060312: Swift XRT team refined analysis
  58. GRB060306: APO Ks-band Imaging Observations
  59. GRB 060312: ROTSE-III Optical Limits
  60. GRB 060312: Swift detection of a burst
  61. Bright short hard GRB 060303: IPN localization and Konus spectrum
  62. GRB060218: analysis of the XMM-Newton observation
  63. Swift/UVOT observations of GRB060306
  64. GRB 060306: Swift-BAT refined analysis
  65. GRB 060306: Swift-XRT team refined analysis
  66. GRB 060306: Swift detection of a bright burst
  67. GRB060218: Ep,i - Eiso correlation
  68. GRB 060223b: Swift/UVOT Upper Limits
  69. GRB 060223B: Swift XRT possible afterglow
  70. GRB 060223B: Swift-BAT refined analysis
  71. GRB 060223a: Swift/UVOT refined analysis
  72. GRB 060223: Swift XRT Team preliminary analysis
  73. GRB 060218/SN 2006aj: Swift-BAT fluence and peak flux
  74. GRB 060223B: Swift detection of a bright burst
  75. GRB 060223: Swift-BAT refined analysis
  76. GRB 060223: Swift/UVOT Confirmation of Optical Afterglow
  77. GRB 060223: Swift detection of a burst
  78. GRB 060219: Swift-BAT refined analysis
  79. GRB 060218: Further refined analysis of the Swift-BAT burst
  80. GRB 060218: Likely an underluminous GRB
  81. GRB 060219: SDSS galaxy inside XRT error circle
  82. GRB060218: UV Detection and Light Curves
  83. GRB 060219: Swift/UVOT Upper Limits
  84. GRB 060219: Swift-XRT Team refined analysis
  85. GRB 051221B: Swift-XRT Team Refined Analysis
  86. GRB 060219: Partial refined analysis of the Swift-BAT burst
  87. GRB 060219: Swift-XRT position typo correction
  88. GRB 060219: Swift-XRT position
  89. GRB 060218: optical/nIR observations at La Palma
  90. GRB 060219: Swift-BAT detection of a weak burst
  91. Oddball GRB 060218, transient or GRB?
  92. GRB060218: Swift/XRT Team preliminary analysis of the possible burst
  93. Brightening of the Optical Counterpart of the Possible GRB 060218
  94. GRB 060218: MDM Observations
  95. GRB 060218A: ROTSE-III Possible Optical Flare
  96. GRB060218: Swift/XRT refined position of a possible burst
  97. Preliminary refined analysis of the Swift-BAT trigger 191157
  98. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  99. GRB 060211B: Swift/UVOT Upper Limits
  100. GRB 060218: Swift XRT Position

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