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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"

27029 results found.

  1. Konus-Wind observations of short/hard GRB 090715A
  2. GRB 090715B: MASTER optical limit
  3. GRB 090715A: Swift-BAT refined analysis
  4. GRB 090715B: Swift/UVOT followup observations
  5. GRB 090715B: break in the optical afterglow decay
  6. GRB 090715B: Swift XRT Refined Analysis
  7. GRB 090715B: Swift-BAT refined analysis
  8. GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
  9. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  10. GRB 090715A: ROTSE-III Optical Limits
  11. GRB 090715: Swift detection of a short hard burst
  12. GRB090713 optical limit by "Pi of the Sky"
  13. GRB 090712: Fermi GBM observation
  14. GRB 090713: Fermi GBM detection
  15. GRB 090712: Swift-BAT refined analysis
  16. GRB 090712: Swift detection of a burst
  17. GRB 090709A: Xinglong TNT optical upper limit
  18. GRB 090709A: Suzaku WAM observation of the prompt emission
  19. GRB 090709A: Swift UVOT upper limits
  20. GRB 090709B: Fermi GBM detection
  21. GRB 090709A: P60 Observations
  22. GRB 090709A: NOT optical observations
  23. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  24. GRB 090709A: Swift XRT Refined Analysis
  25. GRB 090709B, Swift-BAT refined analysis
  26. GRB 090709A: Swift-BAT refined analysis
  27. GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
  28. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  29. GRB 090709A, RIMOTS optical upper limits
  30. GRB 090709B: Swift detection of a burst
  31. GRB 090708 : Fermi GBM detection
  32. GRB 090626: Suzaku WAM observation of the prompt emission
  33. GRB 090709: PAIRITEL NIR Upper Limits
  34. GRB 090704: Fermi GBM observation
  35. GRB 090709: ROTSE-III Optical Limits
  36. GRB 090709: Swift detection of a bright burst
  37. GRB 090708: Early RAPTOR Optical Limits
  38. GRB 090708, Swift-BAT refined analysis
  39. GRB 090708: ROTSE-III Optical Limits
  40. GRB 090708: Swift detection of a burst
  41. GRB 090704: a long GRB found in INTEGRAL off-line analysis
  42. GRB 090706: Fermi GBM detection
  43. Swift-BAT trigger 356516 is not a GRB
  44. Possible GRB090705: Swift-XRT observations
  45. GRB 090705: PAIRITEL NIR Observations
  46. GRB 090705: Swift detection of a possible burst
  47. GRB 090703: Fermi GBM detection
  48. GRB 090702: UVOT upper limits
  49. XRF 090702: Swift-XRT afterglow position
  50. GRB 090701: Fermi GBM detection
  51. GRB 090628: Swift XRT refined analysis
  52. GRB 090630: Fermi GBM detection
  53. GRB 090628: Swift/UVOT Upper Limits
  54. Konus-Wind observation of GRB 090626
  55. GRB080628: SAO RAS optical observations
  56. GRB 090628: Swift-BAT refined analysis
  57. GRB 090628: GROND upper limits
  58. GRB 090626: IPN localization
  59. GRB 090628: Swift/UVOT Finding Chart Observation
  60. GRB 090628: Swift XRT position
  61. GRB 090628: Swift detection of a burst
  62. Fermi LAT observations of GRB 090626
  63. GRB 090625B: Fermi GBM observation
  64. GRB 090625B: Swift-XRT refined analysis
  65. GRB 090626: Fermi GBM detection
  66. GRB 090623: Suzaku WAM observation of the prompt emission
  67. GRB 090618: SARA Second Epoch Observations
  68. GRB 090625B: Faulkes Telescope South observations
  69. GRB 090625: Fermi GBM detection
  70. GRB 090617: Suzaku WAM observation of the prompt emission
  71. GRB 090618: Suzaku WAM observation of the prompt emission
  72. GRB 090623: Fermi GBM detection
  73. GRB 090621B: GRT Optical Observation
  74. GRB 090621A: GRT Optical Observation
  75. PAIRITEL observations of GRB 090618
  76. GRB 090621B: Fermi GBM detection
  77. GRB 090621D: Fermi GBM detection
  78. GRB 090621C: Fermi GBM detection
  79. GRB 090621: Fermi GBM observation
  80. GRB 090620: Fermi GBM detecion
  81. GRB 090621B: Swift/UVOT Upper Limits
  82. GRB 090621B: Swift-BAT refined analysis
  83. GRB 090621B: Swift-XRT refined analysis
  84. GRB 090621A: Swift-BAT refined analysis
  85. GRB 090621B: Swift detection of a short hard burst
  86. GRB 090621: Swift/UVOT Upper Limits
  87. GRB 090621: Swift-XRT Team refined analysis
  88. GRB 090618: BOAO V-band Observation
  89. GRB 090621: Swift detection of a burst
  90. GRB 090618: Fermi GBM observation
  91. GRB 090618, Swift-BAT refined spectral analysis
  92. GRB090618 - Continued optical monitoring and light curve break
  93. GRB 090618: Swift-BAT refined analysis
  94. GRB 090618: SARA observations
  95. GRB090618: Swift-XRT team refined analysis
  96. GRB090618: Swift/UVOT bright afterglow detection
  97. GRB 090617: Fermi GBM detection
  98. GRB 090618: LOAO R-band Observation
  99. GRB 090618 Faulkes Telescope North observations
  100. Optical observations of GRB 090618

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