Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. See news and announcements

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"

18673 results found.

  1. GRB060427: Swift XRT Team refined analysis
  2. GRB060418: Swift XRT Team Further Refined Analysis
  3. GRB 060427, optical observation
  4. GRB 060427: Swift detection of a burst
  5. GRB 060425: IPN localization and KW spectrum of a short, hard burst
  6. GRB 060424: Refined analysis of the Swift-BAT burst
  7. GRB 060424: Swift detection of a burst
  8. Swift-BAT detection of Mrk 421
  9. GRB060421: Swift/UVOT observations
  10. GRB 060421: Swift-BAT Refined Analysis
  11. GRB 060421: Swift-XRT refined analysis
  12. GRB 060418: prediction of t_break
  13. Konus-Wind observation of GRB 060418
  14. GRB(?)060421:MASTER optical limit
  15. GRB(?)060421 : XRT position
  16. Possible GRB060421: BART limits
  17. GRB(?) 060421: Swift detection of a burst
  18. GRB060418: Swift/UVOT Observations
  19. GRB 060418: FRAM early afterglow observation
  20. GRB 060418: Refined Analysis of the Swift-BAT burst
  21. VLT/UVES observations of GRB060418
  22. GRB060418: Swift XRT Team Refined Analysis
  23. GRB060418: Magellan/MIKE Spectroscopic Redshift
  24. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  25. SGR 1900+14: Refined analysis of the Swift-BAT outburst
  26. GRB060413: Swift/UVOT upper limits
  27. SGR 1900+14: Swift detection of an outburst
  28. GRB 060413: Refined analysis of the Swift-BAT burst
  29. GRB 060413: XRT refined analysis
  30. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  31. GRB 060413: Swift detection of a burst
  32. GRB060403: XRT refined analysis
  33. GRB 060403: Swift/UVOT upper limits
  34. SGR 1900+14: BAT observations
  35. GRB 060403: Refined analysis of the Swift-BAT burst
  36. GRB060403: Swift XRT refined position
  37. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  38. GRB 060403: Swift detection of a burst
  39. GRB060331: Swift/UVOT upper limits
  40. Swift XRT observations of the HETE transient H4043
  41. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  42. SGR 1900+14: Swift-BAT detection of a cluster of outbursts
  43. SGR 1900+14: Swift-BAT detection of a bright outburst
  44. GRB 060323 : WIDGET simultaneous optical observations
  45. GRB 060322: Confirmation of Swift XRT afterglow
  46. GRB060323: optical limit
  47. SGR 1900+14: CORRECTION to GCN 4923
  48. SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
  49. SGR 1900+14: Swift detection of renewed activity
  50. GRB060323: NOT optical observations
  51. GRB 060322: IAC80 optical observations
  52. GRB 060322: Swift XRT afterglow candidate
  53. GRB 060323: Swift/UVOT Observations
  54. GRB060323: NOT observations
  55. GRB 060323: Refined analysis of the Swift-BAT burst
  56. GRB 060323: Swift XRT refined analysis
  57. GRB 060323: Swift/XRT position
  58. GRB 060322: Refined analysis of the Swift-BAT burst
  59. GRB060323 - SDSS Pre-Burst Observations
  60. GRB 060323: Swift detection of a burst with a possible optical afterglow
  61. GRB 060322: Swift-BAT detection of a 200-sec burst
  62. GRB 060319: IAC-80 optical observations
  63. GRB060319: Swift XRT refined analysis
  64. GRB060319: Swift/UVOT upper limits
  65. GRB 060319: Swift-BAT refined analysis
  66. GRB060319: Swift/XRT position
  67. GRB 060319: Swift detection of a burst
  68. Konus-Wind observation of GRB 060313
  69. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  70. GRB 060313: Swift/UVOT Observations
  71. GRB 060313: Swift-XRT team refined analysis
  72. GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
  73. GRB 060313: Swift XRT position
  74. GRB060313: optical and near infrared observations with REM
  75. GRB 060313: Swift-BAT detection of a bright short hard burst
  76. GRB060312: Swift UVOT observation
  77. GRB 060312: Refined analysis of the Swift-BAT burst
  78. GRB 060312: Swift XRT team refined analysis
  79. GRB060306: APO Ks-band Imaging Observations
  80. GRB 060312: ROTSE-III Optical Limits
  81. GRB 060312: Swift detection of a burst
  82. Bright short hard GRB 060303: IPN localization and Konus spectrum
  83. GRB060218: analysis of the XMM-Newton observation
  84. Swift/UVOT observations of GRB060306
  85. GRB 060306: Swift-BAT refined analysis
  86. GRB 060306: Swift-XRT team refined analysis
  87. GRB 060306: Swift detection of a bright burst
  88. GRB060218: Ep,i - Eiso correlation
  89. GRB 060223b: Swift/UVOT Upper Limits
  90. GRB 060223B: Swift XRT possible afterglow
  91. GRB 060223B: Swift-BAT refined analysis
  92. GRB 060223a: Swift/UVOT refined analysis
  93. GRB 060223: Swift XRT Team preliminary analysis
  94. GRB 060218/SN 2006aj: Swift-BAT fluence and peak flux
  95. GRB 060223B: Swift detection of a bright burst
  96. GRB 060223: Swift-BAT refined analysis
  97. GRB 060223: Swift/UVOT Confirmation of Optical Afterglow
  98. GRB 060223: Swift detection of a burst
  99. GRB 060219: Swift-BAT refined analysis
  100. GRB 060218: Further refined analysis of the Swift-BAT burst

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov