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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"

18401 results found.

  1. GRB 060502: Swift-BAT refined analysis
  2. GRB 060502: APO Spectroscopic Observations
  3. GRB060501: Swift UVOT followup observations
  4. GRB060502: Super-LOTIS Observations
  5. GRB 060502: Swift detection of a burst with an optical counterpart
  6. GRB 060501: MDM Observations
  7. GRB060501: Super-LOTIS observations
  8. GRB060501: P60 imaging and afterglow candidate
  9. GRB 060501: Refined analysis of the Swift-BAT burst
  10. GRB060501: Swift XRT position
  11. GRB 060501: ROTSE-III Optical Limits
  12. GRB 060501: Swift detection of a burst
  13. GRB060428B: optical observation
  14. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  15. GRB 060428B: MDM Observations
  16. GRB060428B: Swift XRT Team refined analysis
  17. GRB 060427B: IPN localization of a short hard burst
  18. GRB 060428B: Refined analysis of the Swift-BAT burst
  19. GRB 060428B: KAIT observations
  20. GRB060428A: Swift/UVOT observations.
  21. GRB060428B, optical observation
  22. GRB 060428A: Refined analysis of the Swift-BAT burst
  23. GRB060428A: Swift XRT Team refined analysis
  24. GRB 060428B: Swift detection of a burst
  25. GRB 060428: Swift detection of a burst
  26. GRB 060427: NOT observations
  27. GRB 060427: Swift/UVOT upper limits.
  28. GRB 060427: Refined analysis of the Swift-BAT burst
  29. GRB060427: Swift XRT Team refined analysis
  30. GRB060418: Swift XRT Team Further Refined Analysis
  31. GRB 060427, optical observation
  32. GRB 060427: Swift detection of a burst
  33. GRB 060425: IPN localization and KW spectrum of a short, hard burst
  34. GRB 060424: Refined analysis of the Swift-BAT burst
  35. GRB 060424: Swift detection of a burst
  36. Swift-BAT detection of Mrk 421
  37. GRB060421: Swift/UVOT observations
  38. GRB 060421: Swift-BAT Refined Analysis
  39. GRB 060421: Swift-XRT refined analysis
  40. GRB 060418: prediction of t_break
  41. Konus-Wind observation of GRB 060418
  42. GRB(?)060421:MASTER optical limit
  43. GRB(?)060421 : XRT position
  44. Possible GRB060421: BART limits
  45. GRB(?) 060421: Swift detection of a burst
  46. GRB060418: Swift/UVOT Observations
  47. GRB 060418: FRAM early afterglow observation
  48. GRB 060418: Refined Analysis of the Swift-BAT burst
  49. VLT/UVES observations of GRB060418
  50. GRB060418: Swift XRT Team Refined Analysis
  51. GRB060418: Magellan/MIKE Spectroscopic Redshift
  52. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  53. SGR 1900+14: Refined analysis of the Swift-BAT outburst
  54. GRB060413: Swift/UVOT upper limits
  55. SGR 1900+14: Swift detection of an outburst
  56. GRB 060413: Refined analysis of the Swift-BAT burst
  57. GRB 060413: XRT refined analysis
  58. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  59. GRB 060413: Swift detection of a burst
  60. GRB060403: XRT refined analysis
  61. GRB 060403: Swift/UVOT upper limits
  62. SGR 1900+14: BAT observations
  63. GRB 060403: Refined analysis of the Swift-BAT burst
  64. GRB060403: Swift XRT refined position
  65. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  66. GRB 060403: Swift detection of a burst
  67. GRB060331: Swift/UVOT upper limits
  68. Swift XRT observations of the HETE transient H4043
  69. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  70. SGR 1900+14: Swift-BAT detection of a cluster of outbursts
  71. SGR 1900+14: Swift-BAT detection of a bright outburst
  72. GRB 060323 : WIDGET simultaneous optical observations
  73. GRB 060322: Confirmation of Swift XRT afterglow
  74. GRB060323: optical limit
  75. SGR 1900+14: CORRECTION to GCN 4923
  76. SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
  77. SGR 1900+14: Swift detection of renewed activity
  78. GRB060323: NOT optical observations
  79. GRB 060322: IAC80 optical observations
  80. GRB 060322: Swift XRT afterglow candidate
  81. GRB 060323: Swift/UVOT Observations
  82. GRB060323: NOT observations
  83. GRB 060323: Refined analysis of the Swift-BAT burst
  84. GRB 060323: Swift XRT refined analysis
  85. GRB 060323: Swift/XRT position
  86. GRB 060322: Refined analysis of the Swift-BAT burst
  87. GRB060323 - SDSS Pre-Burst Observations
  88. GRB 060323: Swift detection of a burst with a possible optical afterglow
  89. GRB 060322: Swift-BAT detection of a 200-sec burst
  90. GRB 060319: IAC-80 optical observations
  91. GRB060319: Swift XRT refined analysis
  92. GRB060319: Swift/UVOT upper limits
  93. GRB 060319: Swift-BAT refined analysis
  94. GRB060319: Swift/XRT position
  95. GRB 060319: Swift detection of a burst
  96. Konus-Wind observation of GRB 060313
  97. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  98. GRB 060313: Swift/UVOT Observations
  99. GRB 060313: Swift-XRT team refined analysis
  100. GRB 060313: Refined analysis of the Swift-BAT bright short hard burst

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