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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"

35264 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. GRB 060801: optical observations at Hanle and Calar Alto
  8. GRB060801: optical upper limit in R
  9. GRB 060801: Swift XRT refined analysis
  10. GRB 060801: Refined analysis of the Swift-BAT short hard burst
  11. GRB 060801, optical observation
  12. GRB 060801: Kanazawa Optical Observation
  13. GRB 060801: Swift detection of a short burst
  14. GRB060729: ROTSE-III Observations of the Slow Optical Decay
  15. GRB 060218 / SN 2006aj Nebular Spectrum
  16. IBAS Alert n. 3415: not a GRB
  17. Swift-BAT trigger 221873 is not a GRB or a Transient
  18. GRB 060729 redshift
  19. GRB 060719: TORTOREM optical upper limits
  20. GRB 060729: Swift/UVOT Detections
  21. GRB 060729: Refined analysis of the Swift-BAT burst
  22. GRB 060729: Swift-XRT refined analysis
  23. GRB 060729 : Planned XMM-Newton observation
  24. GRB 060729: Swift/UVOT Observations
  25. GRB 060729: ROTSE-III Detection of Optical Counterpart
  26. GRB 060729: Swift detection of a burst with an UVOT optical counterpart
  27. GRB 060728: Swift/UVOT Upper Limits
  28. GRB 060728: Refined analysis of the Swift-BAT burst
  29. GRB 060728, SMARTS optical/IR observations
  30. GRB 060728: Swift detection of a burst
  31. GRB060614 ATCA Radio Limits
  32. GRB 060218 (SN 2006aj): IR afterglow detection six months after the
  33. GRB 060714: Swift/UVOT Observations
  34. GRB 060714: NOT observations
  35. GRB 060719: near-infrared afterglow
  36. GRB 060719: correction to the coordinates reported in GCN 5347
  37. GRB 060522: VLA observation
  38. GRB 060719: Swift/UVOT Upper Limits
  39. GRB 060719: VLT/ISAAC observations
  40. GRB 060719: Refined analysis of the Swift-BAT burst
  41. GRB 060719: XRT refined analysis
  42. GRB 060719: further analysis of VLT observations
  43. GRB 060719: optical limit by Pi-of-the-Sky
  44. GRB060719: FRAM early follow-up limit
  45. GRB 060719: prompt PROMPT observations
  46. GRB060719: REM NIR Observations
  47. GRB 060719: Continued LCO optical observations
  48. GRB 060719: VLT observations
  49. GRB 060719: LCO optical observations
  50. GRB 060719: Swift detection of a burst
  51. GRB 060717: Swift XRT refined analysis
  52. GRB 060714: OA fading and a possible host detection
  53. GRB060714: optical observations
  54. GRB 060717: NOT observations
  55. GRB 060714: Refined analysis of the Swift-BAT burst
  56. GRB 060717 optical upper limit
  57. GRB060717: Swift/UVOT upper limits
  58. GRB 060717: Swift XRT refined position
  59. GRB 060717: Swift-BAT refined analysis
  60. GRB060717 - SDSS Pre-burst Observations
  61. GRB 060714: REM infrared observations
  62. GRB 060717, optical observation
  63. GRB 060717: Swift detection of a burst
  64. GRB060714: correction to GCN 5324
  65. GRB060714: optical observations
  66. GRB 060714, SMARTS optical/IR afterglow observation
  67. GRB 060714 : Liverpool Telescope Observations
  68. GRB 060714: Swift XRT refined analysis
  69. GRB 060714: OA redshift
  70. GRB 060708: VLT spectroscopy
  71. GRB060708: MARGE low resolution spectrum observations
  72. GRB060714: optical observations
  73. Swift-BAT trigger 219136 is not a GRB
  74. Correction to Circular 5314: Circular refers to GRB 060714
  75. GRB060707 possible optical confirmation
  76. Swift trigger 219136 is probably not a GRB
  77. GRB 060714, optical observation
  78. GRB 060714: Swift detection of a burst with an UVOT optical afterglow
  79. GRB 060605: SkyNet Optical Limits
  80. GRB060712: P60 Observations
  81. GRB 060712: XRT refined analysis
  82. GRB 060712: Swift/UVOT Upper Limits
  83. GRB060526: optical observations
  84. GRB 060712: XRT refined position
  85. GRB 060712: Refined analysis of the Swift-BAT burst
  86. GRB060712: MASTER optical observation
  87. GRB120706: MASTER optical observation
  88. GRB 060712: Swift detection of a burst
  89. Host galaxy of GRB050904: 250 GHz upper limit with MAMBO at the IRAM 30m
  90. GRB 060708: PROMPT Optical Limits
  91. GRB 060707: OA fading and redshift
  92. GRB 060708: Swift-XRT refined analysis
  93. GCN 060708: Swift-UVOT Observations
  94. GRB 060708: Refined analysis of the Swift-BAT burst
  95. GCN 060707: Swift-UVOT observations
  96. GRB 060707: Swift-XRT refined analysis
  97. GRB 060708: Swift detection of a burst with an UVOT countpart
  98. GRB060707 possible optical confirmation
  99. GRB 060707: BOOTES-IR optical afterglow candidate
  100. GRB 060707: Refined analysis of the Swift-BAT burst

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