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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"

37797 results found.

  1. IBAS Alert 3418: not a GRB
  2. GRB 060801: WSRT Radio Observations
  3. GRB 060801: XRT/SDSS Frame Offset and Refined XRT Position
  4. GRB060801: Radio Observations
  5. GRB 051109B: Bright spiral host galaxy at low redshift
  6. GRB 060801: optical observations at FORS2/VLT
  7. GRB060801: Swift/UVOT Upper Limits
  8. GRB 060801: optical observations at Hanle and Calar Alto
  9. GRB060801: optical upper limit in R
  10. GRB 060801: Swift XRT refined analysis
  11. GRB 060801: Refined analysis of the Swift-BAT short hard burst
  12. GRB 060801, optical observation
  13. GRB 060801: Kanazawa Optical Observation
  14. GRB 060801: Swift detection of a short burst
  15. GRB060729: ROTSE-III Observations of the Slow Optical Decay
  16. GRB 060218 / SN 2006aj Nebular Spectrum
  17. IBAS Alert n. 3415: not a GRB
  18. Swift-BAT trigger 221873 is not a GRB or a Transient
  19. GRB 060729 redshift
  20. GRB 060719: TORTOREM optical upper limits
  21. GRB 060729: Swift/UVOT Detections
  22. GRB 060729: Refined analysis of the Swift-BAT burst
  23. GRB 060729: Swift-XRT refined analysis
  24. GRB 060729 : Planned XMM-Newton observation
  25. GRB 060729: Swift/UVOT Observations
  26. GRB 060729: ROTSE-III Detection of Optical Counterpart
  27. GRB 060729: Swift detection of a burst with an UVOT optical counterpart
  28. GRB 060728: Swift/UVOT Upper Limits
  29. GRB 060728: Refined analysis of the Swift-BAT burst
  30. GRB 060728, SMARTS optical/IR observations
  31. Swift/XRT preliminary analysis
  32. GRB 060728: Swift detection of a burst
  33. GRB060614 ATCA Radio Limits
  34. GRB 060218 (SN 2006aj): IR afterglow detection six months after the
  35. GRB 060714: Swift/UVOT Observations
  36. GRB 060714: NOT observations
  37. GRB 060719: near-infrared afterglow
  38. GRB 060719: correction to the coordinates reported in GCN 5347
  39. GRB 060522: VLA observation
  40. GRB 060719: Swift/UVOT Upper Limits
  41. GRB 060719: VLT/ISAAC observations
  42. GRB 060719: Refined analysis of the Swift-BAT burst
  43. GRB 060719: XRT refined analysis
  44. GRB 060719: further analysis of VLT observations
  45. GRB 060719: optical limit by Pi-of-the-Sky
  46. GRB060719: FRAM early follow-up limit
  47. GRB 060719: prompt PROMPT observations
  48. GRB060719: REM NIR Observations
  49. GRB 060719: Continued LCO optical observations
  50. GRB 060719: VLT observations
  51. GRB 060719: LCO optical observations
  52. GRB 060719: Swift detection of a burst
  53. GRB 060717: Swift XRT refined analysis
  54. GRB 060714: OA fading and a possible host detection
  55. GRB060714: optical observations
  56. GRB 060717: NOT observations
  57. GRB 060714: Refined analysis of the Swift-BAT burst
  58. GRB 060717 optical upper limit
  59. GRB060717: Swift/UVOT upper limits
  60. GRB 060717: Swift XRT refined position
  61. GRB 060717: Swift-BAT refined analysis
  62. GRB060717 - SDSS Pre-burst Observations
  63. GRB 060714: REM infrared observations
  64. GRB 060717, optical observation
  65. GRB 060717: Swift detection of a burst
  66. GRB060714: correction to GCN 5324
  67. GRB060714: optical observations
  68. GRB 060714, SMARTS optical/IR afterglow observation
  69. GRB 060714 : Liverpool Telescope Observations
  70. GRB 060714: Swift XRT refined analysis
  71. GRB 060714: OA redshift
  72. GRB 060708: VLT spectroscopy
  73. GRB060708: MARGE low resolution spectrum observations
  74. GRB060714: optical observations
  75. Swift-BAT trigger 219136 is not a GRB
  76. Correction to Circular 5314: Circular refers to GRB 060714
  77. GRB060707 possible optical confirmation
  78. Swift trigger 219136 is probably not a GRB
  79. GRB 060714, optical observation
  80. GRB 060714: Swift detection of a burst with an UVOT optical afterglow
  81. GRB 060605: SkyNet Optical Limits
  82. GRB060712: P60 Observations
  83. GRB 060712: XRT refined analysis
  84. GRB 060712: Swift/UVOT Upper Limits
  85. GRB060526: optical observations
  86. GRB 060712: XRT refined position
  87. GRB 060712: Refined analysis of the Swift-BAT burst
  88. GRB060712: MASTER optical observation
  89. GRB120706: MASTER optical observation
  90. GRB 060712: Swift detection of a burst
  91. Host galaxy of GRB050904: 250 GHz upper limit with MAMBO at the IRAM 30m
  92. GRB 060708: PROMPT Optical Limits
  93. GRB 060707: OA fading and redshift
  94. GRB 060708: Swift-XRT refined analysis
  95. GCN 060708: Swift-UVOT Observations
  96. GRB 060708: Refined analysis of the Swift-BAT burst
  97. GCN 060707: Swift-UVOT observations
  98. GRB 060707: Swift-XRT refined analysis
  99. GRB 060708: Swift detection of a burst with an UVOT countpart
  100. GRB060707 possible optical confirmation

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Download all Circulars as a .tar.gz archive (updated once a day):
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