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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"

19598 results found.

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

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