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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"

19607 results found.

  1. GRB 090709A: Swift XRT Refined Analysis
  2. GRB 090709B, Swift-BAT refined analysis
  3. GRB 090709A: Swift-BAT refined analysis
  4. GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
  5. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  6. GRB 090709A, RIMOTS optical upper limits
  7. GRB 090709A: Enhanced Swift-XRT position
  8. GRB 090709B: Swift detection of a burst
  9. GRB 090708 : Fermi GBM detection
  10. GRB 090709: Faulkes Telescope North Upper Limits
  11. GRB 090709: PAIRITEL NIR Upper Limits
  12. GRB 090709: ROTSE-III Optical Limits
  13. GRB 090709: Swift detection of a bright burst
  14. GRB 090708: Early RAPTOR Optical Limits
  15. GRB 090708, Swift-BAT refined analysis
  16. GRB 090708: ROTSE-III Optical Limits
  17. GRB 090708: Swift detection of a burst
  18. Swift-BAT trigger 356516 is not a GRB
  19. Possible GRB090705: Swift-XRT observations
  20. GRB 090705: PAIRITEL NIR Observations
  21. GRB 090705: Swift detection of a possible burst
  22. XRF 090702 : RTT150 optical observations
  23. GRB 090618: Mondy optical observations
  24. GRB 090529: CrAO optical upper limit
  25. GRB 090529: MTM-500 optical observations
  26. GRB 090529: Mt.Terskol optical observations
  27. XRF 090702: Swift-XRT refined analysis
  28. GRB 090702: UVOT upper limits
  29. XRF 090702: Swift-XRT afterglow position
  30. GRB 090628: Swift XRT refined analysis
  31. GRB 090618: RTT150 optical observations
  32. GRB 090628: Swift/UVOT Upper Limits
  33. GRB 090628: Swift-BAT refined analysis
  34. GRB 090628: GROND upper limits
  35. GRB 090628: Enhanced Swift-XRT position
  36. GRB 090626: IPN localization
  37. GRB 090628: Swift/UVOT Finding Chart Observation
  38. GRB 090628: Swift XRT position
  39. GRB 090628: Swift detection of a burst
  40. GRB 090625B: Swift/UVOT Upper Limits
  41. GRB 090625B: Swift-XRT refined analysis
  42. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  43. GRB 090621A: Enhanced Swift-XRT position
  44. GRB 090621B: GRT Optical Observation
  45. GRB 090621A: GRT Optical Observation
  46. PAIRITEL observations of GRB 090618
  47. GRB 090621B: Fermi GBM detection
  48. GRB 090621B: I-band observations from 1.23m CAHA
  49. GRB 090621: Fermi GBM observation
  50. GRB 090621B: Swift/UVOT Upper Limits
  51. GRB 090621B: Swift-BAT refined analysis
  52. GRB 090621B: Swift-XRT refined analysis
  53. GRB 090621B: RTT150 optical observations
  54. GRB 090618: RTT150 optical observations
  55. GRB 090621A: Swift-BAT refined analysis
  56. GRB 090621B: Swift detection of a short hard burst
  57. GRB 090621: Swift/UVOT Upper Limits
  58. GRB 090621: Swift-XRT Team refined analysis
  59. GRB 090621: Swift detection of a burst
  60. GRB 090618: ZTSh optical observations
  61. GRB090618, underlying supernova search
  62. GRB 090618: Fermi GBM observation
  63. GRB 090618, Swift-BAT refined spectral analysis
  64. GRB090618 - Continued optical monitoring and light curve break
  65. GRB 090618: Swift-BAT refined analysis
  66. GRB090618: Swift-XRT team refined analysis
  67. GRB090618: Swift/UVOT bright afterglow detection
  68. Swift XRT observations of GRB 090531A
  69. GRB 090618: AGILE observations
  70. GRB 090618: Enhanced Swift-XRT position
  71. GRB 090618 Faulkes Telescope North observations
  72. GRB 090618: ROTSE-III Detection of Optical Counterpart
  73. GRB090618: P60 Optical Afterglow
  74. GRB 090618: Swift detection of a bright burst with optical afterglow
  75. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  76. RXTE Discovery of Pulsations from SGR 0418+5729
  77. GRB 090531B: Fermi GBM detection
  78. Discovery of a new soft gamma repeater source, SGR 0418+5729
  79. GRB 090607: XRT Team Refined Analysis
  80. GRB 090607: Swift/UVOT Upper Limits
  81. GRB 090607: Swift-BAT refined analysis of the SHB
  82. GRB 090607: Faulkes Telescope North observations
  83. GRB 090607: Swift detection of a burst
  84. Ignore GCN/Swift-BAT Lightcurve Notices for trigger 353567
  85. GRB 090530: RTT150 Optical Observation
  86. GRB 090529A: RTT150 Optical Observations
  87. GRB 090531B: GROND observation
  88. GRB 090530: Early RAPTOR Optical Observations
  89. GRB 090531B: Swift/BAT spectral lag results
  90. Corrections to GRB 090531B Swift/UVOT Upper Limits
  91. GRB 090531B, RIMOTS optical upper limits
  92. GRB 090531B: Swift/UVOT Upper Limits
  93. GRB 090530: GRT Optical Observation
  94. GRB 090531B: Swift-BAT refined analysis
  95. Initial Swift/UVOT observations of GRB 090531B
  96. GRB 090531B: Swift-XRT candidate afterglow position
  97. GRB 090531B: ROTSE-III Optical Limits
  98. GRB 090531B: Swift detection of a burst
  99. GRB 090531: Swift-BAT refined analysis
  100. GRB 090530: break in light curve

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