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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"

27032 results found.

  1. GRB 100526A: Swift XRT refined analysis
  2. GRB 100526B: Swift-BAT refined analysis
  3. GRB 100526B: Swift XRT/UVOT observations
  4. GRB 100526A: Swift-BAT refined analysis
  5. GRB 100526B: Swift detection of a probable GRB
  6. GRB 100526A: Swift detection of a burst
  7. Konus-Wind observation of GRB 100522A
  8. GRB100522A: Suzaku WAM observation of the prompt emission
  9. GRB 100418A: Subaru late-time optical imaging and spectroscopy
  10. Swift/UVOT observations of GRB100522A.
  11. GRB 100522A: Fermi GBM observation
  12. GRB 100522A: Swift XRT refined analysis
  13. GRB 100522A, Swift-BAT refined analysis
  14. GRB 100522A: BOOTES-2 optical limit
  15. GRB 100522A: Swift detection of a burst
  16. GRB 100518A: GROND afterglow observation and photo-z
  17. GRB 100518A: Swift/UVOT Upper Limits
  18. GRB 100518A: Swift-XRT refined analysis
  19. GRB 100518A: optical afterglow decay
  20. Update to the configuration of the Fermi-LAT onboard GRB search
  21. GRB 100518A: Swift target of opportunity observation of the INTEGRAL burst
  22. Swift-BAT trigger 422437 is not anything astrophysical
  23. Swift Trigger 422437 is probably not a GRB
  24. Fermi/GBM trigger 295791986 - unreliable location
  25. GRB 100517A: MASTER-Net wide field camera prompt optical observations
  26. GRB 100514A: Swift/UVOT Observations
  27. GRB 100514A: YNAO-GMG observations
  28. GRB 100514A: Swift XRT refined analysis
  29. GRB 100514A: Swift-BAT refined analysis
  30. GRB 100514A: Faulkes Telescope South observations
  31. GRB 100514A: Swift detection of a burst
  32. GRB 100513A: Faulkes Telescope South observations
  33. GRB 100513A: Swift/UVOT upper limits
  34. GRB 100513A, RIMOTS optical upper limits
  35. GRB 100513A: Swift-BAT refined analysis
  36. GRB 100513A: PAIRITEL NIR afterglow candidate
  37. GRB 100513A: Swift detection of a burst
  38. GRB 100510A: Fermi GBM detection/observation
  39. GRB 100511A: Fermi GBM detection/observation
  40. GRB 100511A: Super-LOTIS early observations
  41. Swift-BAT trigger 421695 is likely not astrophysical
  42. GRB 100510A: MAXI/GSC detection
  43. GRB 100511A, RIMOTS optical upper limits
  44. Trigger 421695: Swift detection of a possible burst
  45. GRB100508A: Further Swift/UVOT Observations
  46. GRB100503A: Suzaku WAM observation of the prompt emission
  47. GRB 100508A: GROND Detection of the optical afterglow
  48. GRB 100508A: Swift-XRT Refined analysis
  49. GRB 100508A: Swift-BAT refined analysis
  50. GRB100508A: Swift/UVOT Detection of the Afterglow
  51. GRB 100508A: ROTSE-III Optical Limits
  52. GRB 100508A: Swift detection of a burst
  53. Fermi Gamma-ray Burst Monitor trigger 294712621 is not a GRB
  54. Swift-BAT refined analysis of trigger 421262
  55. GRB 100504A: Fermi GBM observation
  56. An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
  57. GRB 100504A: Swift/UVOT Observations
  58. GRB 100418A: Flattening of the Swift/UVOT Optical Light Curve
  59. GRB 100504A: GROND Upper limits
  60. GRB 100504A: Swift-BAT refined analysis
  61. GRB 100504A: SARA-South Upper Limit
  62. GRB 100503A: Fermi GBM detection
  63. GRB 100504A: UVOT-enhanced XRT position
  64. GRB 100504A: Swift detection of a burst
  65. Swift-BAT trigger 421072 is not astrophyical
  66. INTEGRAL observations of Swift GRB trigger 421072
  67. GRB100423A : Suzaku WAM observation of the prompt emission
  68. Trigger 421072: Possible Swift detection of a GRB or transient
  69. GRB 100427A: Fermi GBM detection
  70. GRB 100427A detected in ground analysis of Swift BAT data
  71. Konus-Wind observation of GRB 100423A
  72. GRB 100425A: Swift XRT refined analysis
  73. GRB100425A: Swift/UVOT Upper Limits
  74. GRB 100424A: Swift/UVOT Upper Limits
  75. GRB 100425A: Swift-BAT refined analysis
  76. GRB 100425A: GROND afterglow observation
  77. GRB 100424A: D50 optical limits
  78. GRB 100424A : Lulin early z'-band upper limit
  79. GRB 100424A: GROND Upper Limits
  80. GRB 100424A: PAIRITEL NIR Upper Limits
  81. GRB 100424A: Swift-XRT refined analysis
  82. GRB 100425A: Swift detection of a burst
  83. GRB 100424A, Swift-BAT refined analysis
  84. GRB 100424A: Swift detection of a burst
  85. GRB 100420A: GRT Optical Observation
  86. Swift-BAT refined analysis of trigger 420256
  87. Swift Trigger 420256: D50 optical limits
  88. GRB 100420A: Swift-BAT refined analysis
  89. GRB 100423B: Fermi GBM detection
  90. GRB 100423A: Swift-BAT refined analysis
  91. Swift Trigger 420256: IAC80 R-band observations
  92. Swift Trigger 420256: BOOTES-2 observations
  93. Swift Trigger 420256: ROTSE-III Optical Limits
  94. Trigger 420256: Swift detection of a possible GRB
  95. GRB 100423A: Skynet/PROMPT Detections
  96. GRB 100423A: GROND discovery of afterglow
  97. GRB 100423A: Swift detection of a burst
  98. GRB 100418A: Continued PAIRITEL NIR Observations
  99. GRB 100418A: Continuing Swift/UVOT Observations
  100. GRB 100414A: CFHT optical observations

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