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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"

19599 results found.

  1. GRB 090708 : Fermi GBM detection
  2. GRB 090709: Faulkes Telescope North Upper Limits
  3. GRB 090709: PAIRITEL NIR Upper Limits
  4. GRB 090709: ROTSE-III Optical Limits
  5. GRB 090709: Swift detection of a bright burst
  6. GRB 090708: Early RAPTOR Optical Limits
  7. GRB 090708, Swift-BAT refined analysis
  8. GRB 090708: ROTSE-III Optical Limits
  9. GRB 090708: Swift detection of a burst
  10. Swift-BAT trigger 356516 is not a GRB
  11. Possible GRB090705: Swift-XRT observations
  12. GRB 090705: PAIRITEL NIR Observations
  13. GRB 090705: Swift detection of a possible burst
  14. XRF 090702 : RTT150 optical observations
  15. GRB 090618: Mondy optical observations
  16. GRB 090529: CrAO optical upper limit
  17. GRB 090529: MTM-500 optical observations
  18. GRB 090529: Mt.Terskol optical observations
  19. XRF 090702: Swift-XRT refined analysis
  20. GRB 090702: UVOT upper limits
  21. XRF 090702: Swift-XRT afterglow position
  22. GRB 090628: Swift XRT refined analysis
  23. GRB 090618: RTT150 optical observations
  24. GRB 090628: Swift/UVOT Upper Limits
  25. GRB 090628: Swift-BAT refined analysis
  26. GRB 090628: GROND upper limits
  27. GRB 090628: Enhanced Swift-XRT position
  28. GRB 090626: IPN localization
  29. GRB 090628: Swift/UVOT Finding Chart Observation
  30. GRB 090628: Swift XRT position
  31. GRB 090628: Swift detection of a burst
  32. GRB 090625B: Swift/UVOT Upper Limits
  33. GRB 090625B: Swift-XRT refined analysis
  34. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  35. GRB 090621A: Enhanced Swift-XRT position
  36. GRB 090621B: GRT Optical Observation
  37. GRB 090621A: GRT Optical Observation
  38. PAIRITEL observations of GRB 090618
  39. GRB 090621B: Fermi GBM detection
  40. GRB 090621B: I-band observations from 1.23m CAHA
  41. GRB 090621: Fermi GBM observation
  42. GRB 090621B: Swift/UVOT Upper Limits
  43. GRB 090621B: Swift-BAT refined analysis
  44. GRB 090621B: Swift-XRT refined analysis
  45. GRB 090621B: RTT150 optical observations
  46. GRB 090618: RTT150 optical observations
  47. GRB 090621A: Swift-BAT refined analysis
  48. GRB 090621B: Swift detection of a short hard burst
  49. GRB 090621: Swift/UVOT Upper Limits
  50. GRB 090621: Swift-XRT Team refined analysis
  51. GRB 090621: Swift detection of a burst
  52. GRB 090618: ZTSh optical observations
  53. GRB090618, underlying supernova search
  54. GRB 090618: Fermi GBM observation
  55. GRB 090618, Swift-BAT refined spectral analysis
  56. GRB090618 - Continued optical monitoring and light curve break
  57. GRB 090618: Swift-BAT refined analysis
  58. GRB090618: Swift-XRT team refined analysis
  59. GRB090618: Swift/UVOT bright afterglow detection
  60. Swift XRT observations of GRB 090531A
  61. GRB 090618: AGILE observations
  62. GRB 090618: Enhanced Swift-XRT position
  63. GRB 090618 Faulkes Telescope North observations
  64. GRB 090618: ROTSE-III Detection of Optical Counterpart
  65. GRB090618: P60 Optical Afterglow
  66. GRB 090618: Swift detection of a bright burst with optical afterglow
  67. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  68. RXTE Discovery of Pulsations from SGR 0418+5729
  69. GRB 090531B: Fermi GBM detection
  70. Discovery of a new soft gamma repeater source, SGR 0418+5729
  71. GRB 090607: XRT Team Refined Analysis
  72. GRB 090607: Swift/UVOT Upper Limits
  73. GRB 090607: Swift-BAT refined analysis of the SHB
  74. GRB 090607: Faulkes Telescope North observations
  75. GRB 090607: Swift detection of a burst
  76. Ignore GCN/Swift-BAT Lightcurve Notices for trigger 353567
  77. GRB 090530: RTT150 Optical Observation
  78. GRB 090529A: RTT150 Optical Observations
  79. GRB 090531B: GROND observation
  80. GRB 090530: Early RAPTOR Optical Observations
  81. GRB 090531B: Swift/BAT spectral lag results
  82. Corrections to GRB 090531B Swift/UVOT Upper Limits
  83. GRB 090531B, RIMOTS optical upper limits
  84. GRB 090531B: Swift/UVOT Upper Limits
  85. GRB 090530: GRT Optical Observation
  86. GRB 090531B: Swift-BAT refined analysis
  87. Initial Swift/UVOT observations of GRB 090531B
  88. GRB 090531B: Swift-XRT candidate afterglow position
  89. GRB 090531B: ROTSE-III Optical Limits
  90. GRB 090531B: Swift detection of a burst
  91. GRB 090531: Swift-BAT refined analysis
  92. GRB 090530: break in light curve
  93. GRB 090531: GROND upper limits
  94. GRB 090531: Swift detection of a burst
  95. GRB090530: Swift XRT refined analysis
  96. GRB090530: Swift/UVOT afterglow detection
  97. GRB 090529: Swift-XRT refined analysis
  98. GRB 090530: Enhanced Swift-XRT position
  99. GRB 090530: Swift-BAT refined analysis
  100. GRB 090530: PAIRITEL NIR Detections

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