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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"

44619 results found.

  1. GRB 070612A: continued SARA observations
  2. GRB 070612A: spectral lag
  3. GRB 070611: Watcher Observations
  4. Swift Trigger 282176 is Cygnus X-1
  5. GRB 070612A: MDM Observations
  6. GRB 070612A: P60 Confirmation of Afterglow and An Underlying, Nearby
  7. GRB 070612B: SARA upper limit
  8. GRB 070612B, Swift-BAT refined analysis
  9. GRB 070612A, Swift-BAT refined analysis
  10. GRB 070612B: Swift-XRT refined analysis
  11. SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations
  12. GRB 070612B: Swift/UVOT upper limits
  13. GRB 070612B: FRAM limit
  14. GRB070612B: P60 Observations
  15. GRB 070612B: KAIT limits
  16. GRB 070612A: SARA detection of possible OT
  17. GRB 070612B: Swift XRT position from downlink data
  18. GRB 070610: TAROT Calern observatory optical observations
  19. GRB 070610: MITSuME OAO optical upper limit
  20. GRB 070612B: Swift detection of a burst
  21. GRB070612 - SDSS Pre-Burst Observations
  22. GRB 070612: Swift detection of a burst
  23. GRB 070610: OPTIMA-Burst detection of continued strong flaring activity
  24. GRB 070610: SARA upper limit
  25. GRB 070610: Swift-XRT refined analysis
  26. GRB 070610: TLS RRM sees flaring behaviour - Galactic transient?
  27. GRB 070611: Swift/UVOT Observations
  28. GRB 070611: Swift-XRT refined analysis
  29. GRB 070611, Swift-BAT refined analysis
  30. GRB 070610: Optical observations from OSN
  31. GRB 070610: Watcher Observations
  32. GRB 070611: VLT redshift
  33. GRB 060121 : pseudo-z = 1.9 ('intermediate-duration' burst)
  34. GRB 070611: ROTSE-III Detection of Late Rising Optical Counterpart
  35. GRB 070611; Swift-XRT position
  36. GRB 070611: ROTSE-III Optical Limits
  37. GRB 070611: Swift detection of a burst
  38. GRB 070610: Swift-UVOT Upper Limits
  39. GRB 070610: OPTIMA-Burst high-time-resolution optical observations
  40. GRB 070610, Swift-BAT refined analysis
  41. GRB 070610; Swift-XRT position
  42. GRB 070610: Swift detection of a burst
  43. GRB 070412: TAROT Calern observatory optical observations
  44. GRB 070411: TAROT Calern observatory optical observations
  45. GRB 070419A, deep LBT photometry and possible supernova detection
  46. GRB070520B: optical observations
  47. GRB070520: optical observation
  48. GRB070518: optical observation
  49. GRB070521: optical observation
  50. Swift/UVOT refined analysis of GRB070531
  51. GRB 070531: NOT nIR observations
  52. GRB 070531: Swift-BAT refined analysis
  53. GRB 070531: I-band observations from IAC80
  54. GRB 070531: Swift-XRT position
  55. GRB 070531: Liverpool Telescope Optical Observations
  56. GRB 070531: Swift detection of a burst
  57. GRB 070529: SARA upper limit
  58. Swift/UVOT refined analysis of GRB070529
  59. GRB 070529: MARGE Observations
  60. GRB 070529: Optical aterglow from MIRO
  61. GRB 070529: Gemini Redshift
  62. GRB 070529: Swift-XRT refined analysis
  63. GRB 070529, Swift-BAT refined analysis
  64. GRB 070529: Xinglong TNT Optical Upper Limit
  65. GRB 070529: Swift detection of a burst with an optical aterglow
  66. GRB 070412: Deep Keck imaging
  67. Swift Triggers 280447, 280450 and 280451 are invalid
  68. Swift trigger 280447 is probably a Galactic transient
  69. GRB 070518, deep LBT photometry
  70. GRB 070518: MARGE Observations
  71. GRB 070521: pseudo-z ~ 2.28 from prompt emission spectrum
  72. Konus-Wind observation of GRB 070521
  73. GRB 070518: optical observation
  74. GRB070521: Second Epoch Gemini Imaging
  75. GRB070521: NIR observations
  76. GRB070520B: NIR observations
  77. GRB 070521: Swift/UVOT Upper Limits
  78. GRB 070521, optical observation
  79. GRB 070521: Swift-XRT refined analysis
  80. GRB 070521: Keck imaging
  81. GRB070521: Gemini Observations
  82. GROND upper limits of GRB 070521
  83. GRB 070521 Milagro GeV/TeV Observations
  84. GRB 070520B: SARA upper limit
  85. GRB 070520A: SARA upper limit
  86. GRB 070521: SARA upper limit
  87. GRB 070521: Subaru observations and possible host detection
  88. GRB070518: Optical/NIR observation
  89. GRB 070520B: Swift/UVOT Upper Limits
  90. GRB 070520A: Subaru Observations
  91. GRB 070521, Swift-BAT refined analysis
  92. GRB 070520A: Swift UVOT Upper Limits
  93. GRB 070520B: Swift-XRT refined analysis
  94. GRB 070521: optical limit by Pi of the Sky
  95. GRB070521: P200 Observations
  96. GRB070521 : Faulkes Telescope North Observations
  97. GRB 070521: TAROT La Silla observatory optical observations
  98. GRB070521: Bright SDSS Galaxy Near XRT Error Circle
  99. GRB070521 - SDSS Pre-Burst Observations
  100. GRB 070521: Swift detection of a burst

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