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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"
  1. GRB 060801: Kanazawa Optical Observation
  2. GRB 060801: Swift detection of a short burst
  3. GRB060729: ROTSE-III Observations of the Slow Optical Decay
  4. GRB 060218 / SN 2006aj Nebular Spectrum
  5. IBAS Alert n. 3415: not a GRB
  6. Swift-BAT trigger 221873 is not a GRB or a Transient
  7. GRB 060729 redshift
  8. GRB 060719: TORTOREM optical upper limits
  9. GRB 060729: Swift/UVOT Detections
  10. GRB 060729: Refined analysis of the Swift-BAT burst
  11. GRB 060729: Swift-XRT refined analysis
  12. GRB 060729 : Planned XMM-Newton observation
  13. GRB 060729: Swift/UVOT Observations
  14. GRB 060729: ROTSE-III Detection of Optical Counterpart
  15. GRB 060729: Swift detection of a burst with an UVOT optical counterpart
  16. GRB 060728: Swift/UVOT Upper Limits
  17. GRB 060728: Refined analysis of the Swift-BAT burst
  18. GRB 060728, SMARTS optical/IR observations
  19. Swift/XRT preliminary analysis
  20. GRB 060728: Swift detection of a burst
  21. GRB060614 ATCA Radio Limits
  22. GRB 060218 (SN 2006aj): IR afterglow detection six months after the
  23. GRB 060714: Swift/UVOT Observations
  24. GRB060719: prompt NIR observations with REM
  25. GRB 060714: NOT observations
  26. GRB 060719: near-infrared afterglow
  27. GRB 060719: correction to the coordinates reported in GCN 5347
  28. GRB 060522: VLA observation
  29. GRB 060719: Swift/UVOT Upper Limits
  30. GRB 060719: VLT/ISAAC observations
  31. GRB 060719: Refined analysis of the Swift-BAT burst
  32. GRB 060719: XRT refined analysis
  33. GRB 060719: further analysis of VLT observations
  34. GRB 060719: optical limit by Pi-of-the-Sky
  35. GRB060719: FRAM early follow-up limit
  36. GRB 060719: prompt PROMPT observations
  37. GRB060719: REM NIR Observations
  38. GRB 060719: Continued LCO optical observations
  39. GRB 060719: VLT observations
  40. GRB 060719: LCO optical observations
  41. GRB 060719: Swift detection of a burst
  42. GRB 060717: Swift XRT refined analysis
  43. GRB 060714: OA fading and a possible host detection
  44. GRB060714: optical observations
  45. GRB 060717: NOT observations
  46. GRB 060714: Refined analysis of the Swift-BAT burst
  47. GRB 060717 optical upper limit
  48. GRB060717: Swift/UVOT upper limits
  49. GRB 060717: Swift XRT refined position
  50. GRB 060717: Swift-BAT refined analysis
  51. GRB060717 - SDSS Pre-burst Observations
  52. GRB 060714: REM infrared observations
  53. GRB 060717, optical observation
  54. GRB 060717: Swift detection of a burst
  55. GRB060714: correction to GCN 5324
  56. GRB060714: optical observations
  57. GRB 060714, SMARTS optical/IR afterglow observation
  58. GRB 060714 : Liverpool Telescope Observations
  59. GRB 060714: Swift XRT refined analysis
  60. GRB 060714: OA redshift
  61. GRB 060708: VLT spectroscopy
  62. GRB060708: MARGE low resolution spectrum observations
  63. GRB060714: optical observations
  64. Swift-BAT trigger 219136 is not a GRB
  65. Correction to Circular 5314: Circular refers to GRB 060714
  66. GRB060707 possible optical confirmation
  67. Swift trigger 219136 is probably not a GRB
  68. GRB 060714, optical observation
  69. GRB 060714: Swift detection of a burst with an UVOT optical afterglow
  70. GRB 060605: SkyNet Optical Limits
  71. GRB060712: P60 Observations
  72. GRB 060712: XRT refined analysis
  73. GRB 060712: Swift/UVOT Upper Limits
  74. GRB060526: optical observations
  75. GRB 060712: XRT refined position
  76. GRB 060712: Refined analysis of the Swift-BAT burst
  77. GRB060712: MASTER optical observation
  78. GRB120706: MASTER optical observation
  79. GRB 060712: Swift detection of a burst
  80. Host galaxy of GRB050904: 250 GHz upper limit with MAMBO at the IRAM 30m
  81. GRB 060708: PROMPT Optical Limits
  82. GRB 060707: OA fading and redshift
  83. GRB 060708: Swift-XRT refined analysis
  84. GCN 060708: Swift-UVOT Observations
  85. GRB 060708: Refined analysis of the Swift-BAT burst
  86. GCN 060707: Swift-UVOT observations
  87. GRB 060707: Swift-XRT refined analysis
  88. GRB 060708: Swift detection of a burst with an UVOT countpart
  89. GRB060707 possible optical confirmation
  90. GRB 060707: BOOTES-IR optical afterglow candidate
  91. GRB 060707: Refined analysis of the Swift-BAT burst
  92. GRB 060707: BOOTES-IR optical observation
  93. GRB060614: Possible SN Bump in UVOT U Band Light Curve
  94. GRB 060707: Swift detection of a burst
  95. GRB 060515: Upper Limit on Host Galaxy
  96. GRB 050223: Magellan redshift
  97. GRB 060614: SMARTS host galaxy observations
  98. GRB 060614: Detection of a Possible, Late-Time Rebrightening
  99. Correction to GCN 5278 & GCN 5279 (GRBs 060105 & 060109)
  100. GRB 060109: Upper Limit on Host Galaxy

Advanced

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