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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').

18341 results found.

  1. Swift Trigger 282176 is Cygnus X-1
  2. GRB 070612A: MDM Observations
  3. GRB 070612B, Swift-BAT refined analysis
  4. GRB 070612A, Swift-BAT refined analysis
  5. GRB 070612B: Swift-XRT refined analysis
  6. SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations
  7. GRB 070612B: Swift/UVOT upper limits
  8. GRB 070612B: FRAM limit
  9. GRB 070612B: KAIT limits
  10. GRB 070612B: Swift XRT position from downlink data
  11. GRB 070610: TAROT Calern observatory optical observations
  12. GRB 070612B: Swift detection of a burst
  13. GRB 070612: Swift detection of a burst
  14. GRB 070610: Swift-XRT refined analysis
  15. GRB 070610: TLS RRM sees flaring behaviour - Galactic transient?
  16. GRB 070611: Swift/UVOT Observations
  17. GRB 070611: Swift-XRT refined analysis
  18. GRB 070611, Swift-BAT refined analysis
  19. GRB 070610: Watcher Observations
  20. GRB 070611: ROTSE-III Detection of Late Rising Optical Counterpart
  21. GRB 070611; Swift-XRT position
  22. GRB 070611: ROTSE-III Optical Limits
  23. GRB 070611: Swift detection of a burst
  24. GRB 070610: Swift-UVOT Upper Limits
  25. GRB 070610: OPTIMA-Burst high-time-resolution optical observations
  26. GRB 070610, Swift-BAT refined analysis
  27. GRB 070610; Swift-XRT position
  28. GRB 070610: Swift detection of a burst
  29. GRB 070412: TAROT Calern observatory optical observations
  30. GRB 070411: TAROT Calern observatory optical observations
  31. Swift/UVOT refined analysis of GRB070531
  32. GRB 070531: Swift-BAT refined analysis
  33. GRB 070531: Swift-XRT position
  34. GRB 070531: Liverpool Telescope Optical Observations
  35. GRB 070531: Swift detection of a burst
  36. Swift/UVOT refined analysis of GRB070529
  37. GRB 070529: MARGE Observations
  38. GRB 070529: Optical aterglow from MIRO
  39. GRB 070529: Swift-XRT refined analysis
  40. GRB 070529, Swift-BAT refined analysis
  41. GRB 070529: Swift detection of a burst with an optical aterglow
  42. GRB 070412: Deep Keck imaging
  43. Swift Triggers 280447, 280450 and 280451 are invalid
  44. Swift trigger 280447 is probably a Galactic transient
  45. GRB 070518: MARGE Observations
  46. GRB 070521: pseudo-z ~ 2.28 from prompt emission spectrum
  47. Konus-Wind observation of GRB 070521
  48. GRB 070521: Swift/UVOT Upper Limits
  49. GRB 070521: Swift-XRT refined analysis
  50. GROND upper limits of GRB 070521
  51. GRB 070521 Milagro GeV/TeV Observations
  52. GRB 070520B: Swift/UVOT Upper Limits
  53. GRB 070521, Swift-BAT refined analysis
  54. GRB 070520A: Swift UVOT Upper Limits
  55. GRB 070520B: Swift-XRT refined analysis
  56. GRB 070521: TAROT La Silla observatory optical observations
  57. GRB070521 - SDSS Pre-Burst Observations
  58. GRB 070521: Swift detection of a burst
  59. GRB 070520B, Swift-BAT refined analysis
  60. GRB 070520A, Swift-BAT refined analysis
  61. GRB 070520A: Swift-XRT refined analysis
  62. GRB 070520B: Swift detection of a burst
  63. GRB 070520: Swift detection of a burst
  64. VLA observation of GRB 070518
  65. GRB 070518: Swift-XRT refined analysis
  66. GRB070518: UVOT refined analysis
  67. GRB 070518, Swift-BAT refined analysis
  68. GRB 070518: Swift detection of a burst with optical afterglow
  69. GRB070517: Swift-XRT Refined Analysis
  70. GRB 070517, Swift-BAT refined analysis
  71. GRB 070517: Swift detection of a burst
  72. GRB 070509: objects inside XRT error circle
  73. GRB 070512: IPN localization and Konus spectrum of a bright burst
  74. GRB 070508: pseudo-z from 4 different spectral analyses
  75. GRB 070509: Swift/UVOT Upper Limits
  76. Konus-Wind and Konus-A observation of GRB 070508
  77. Swift-BAT trigger 278987 is not a GRB
  78. GRB 070510: Swift detection of a possible burst
  79. GRB070509: Swift-XRT Refined Analysis
  80. GRB 070509, Swift-BAT refined analysis
  81. GRB 070508: Suzaku/WAM observation of the prompt emission
  82. GRB 070509: REM observations
  83. GRB 070509: Swift detection of a burst
  84. GRB 070509: ROTSE-III Optical Limits
  85. GRB070508: Swift/UVOT Observations
  86. GRB 070508, Swift-BAT refined analysis
  87. GRB 070508: Swift-XRT refined analysis
  88. GRB 070508: TAROT La Silla observatory optical observations
  89. GRB 070508: Swift detection of an intense burst with an optical counterpart
  90. GRB070412: MAGIC telescope GeV observation
  91. Swift-BAT trigger 278809 is not a GRB
  92. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  93. GRB070506: Swift/UVOT Observations
  94. GRB070506: Swift XRT refined analysis
  95. GRB 070506, Swift-BAT Refined Analysis
  96. GRB 070506: Swift detection of a burst with optical afterglow
  97. GRB 070429A: Swift XRT further analysis
  98. GRB 070309: Swift-XRT afterglow confirmation
  99. VLA observation of GRB 070429B
  100. Swift/UVOT observations of GRB070429B

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