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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 150203A: KAIT Optical Upper Limit
  2. GRB 150203A: Prompt enhanced Swift-XRT position
  3. GRB 150203A: Swift detection of a burst
  4. GRB 150202A: Swift detection of a burst
  5. GRB 150201A: Swift/UVOT Upper Limits
  6. GRB 150201A, Swift-BAT refined analysis
  7. Konus-Wind observation of GRB 150201A
  8. GRB 150201A: GROND upper limits
  9. GRB 150201A: Swift-XRT refined Analysis
  10. GRB 150201A: Fermi GBM observation
  11. GRB 150201A: Enhanced Swift-XRT position
  12. GRB 150201A: Swift detection of a burst
  13. Swift Trigger 629206 is likely 1RXS J180408.9-342058
  14. GRB 150120B: Khureltogot optical observations
  15. GRB 150123A: MASTER inspection
  16. IPN Triangulation of GRB 150127B
  17. Swift Trigger 628458 likely not astrophysical
  18. GRB 150123A: Swift/UVOT observations
  19. GRB 150123A: Swift-XRT observations
  20. GRB 150120B: Mondy optical observations
  21. GRB 150123A Tiled Swift observations
  22. IPN Triangulation of GRB 150118B (long/intense)
  23. GRB 150120A: ISON-NM early optical limit
  24. GRB 150120B: FTN early optical light curve
  25. GRB 150120B: Swift/UVOT Upper Limits
  26. GRB 150120B, Optical observations
  27. GRB 150120B: GROND Afterglow Detection
  28. GRB 150120A: Swift-XRT refined Analysis
  29. GRB 150120A: KAIT Optical Upper Limit
  30. GRB 150120B: Swift-BAT refined analysis
  31. GRB 150120A: Swift-BAT refined analysis
  32. GRB 150101B/Swift J123205.1-105602: TNG NIR follow-up
  33. GRB 150120B: Swift-XRT refined Analysis
  34. GRB 150120A: Swift/UVOT Upper Limits
  35. GRB 150110B: AMI 15 GHz detection of possible radio counterpart
  36. GRB 150101B/Swift J123205.1-105602, deep VLT observations
  37. GRB 150120B: Enhanced Swift-XRT position
  38. GRB 150120A: Fermi GBM observation
  39. GRB 150101B/Swift J123205.1-105602: XMM-Newton observation
  40. GRB 150120A: Enhanced Swift-XRT position
  41. GRB 150120B: FTN optical afterglow confirmation
  42. GRB 150120B: Swift detection of a burst
  43. GRB 150120A: Prompt enhanced Swift-XRT position
  44. GRB 150120A: Swift detection of a possibly-short burst
  45. GRB 150101B/Swift J123205.1-105602: continued WSRT radio and VLT optical observations
  46. Trigger 626581: Swift detection of GRO J1008-57
  47. GRB 150110B: Khureltogot optical upper limit
  48. The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
  49. Swift detection of the variable star SZ Psc
  50. GRB 150110C: Swift/UVOT Upper Limits
  51. GRB 150110C: Swift-XRT observations
  52. GRB 150110B: Swift-BAT refined analysis
  53. GRB 150110C Tiled Swift observations
  54. GRB 150110B: Swift-XRT refined Analysis
  55. GRB 150110B: Swift/UVOT Upper Limits
  56. GRB 150110B: Fermi GBM Detection
  57. GRB 150110B: Enhanced Swift-XRT position
  58. GRB 150110B: Swift detection of a burst
  59. GRB 150101B/Swift J123205.1-105602: Chandra observations
  60. GRB 150101B / Swift J123205.1-105602: 9.8 GHz VLA observations
  61. GRB 150101B/Swift J123205.1-105602: WSRT radio observation
  62. GRB 150101B / Swift J123205.1-105602: X-ray counterpart is likely an AGN
  63. GRB 150101B/Swift J123205.1-105602: VLT observations and redshift
  64. Swift detection of 4U 1700+24 (= V* V934 Her)
  65. GRB 150103A: MASTER optical observations
  66. GRB 150101B: potential host galaxy redshift by GTC
  67. GRB 150103A: Swift-XRT refined Analysis
  68. GRB 150101B: Fermi GBM detection
  69. GRB 150103A: Swift/UVOT Upper Limits
  70. GRB 150103A: Swift-BAT refined analysis
  71. GRB 150103A: Zadko observatory - Gingin optical observations
  72. GRB 150103A: Enhanced Swift-XRT position
  73. Swift J123205.1-105602: Magellan candidate afterglow
  74. GRB 150103A: Prompt enhanced Swift-XRT position
  75. GRB 150103A: Swift detection of a burst
  76. Swift J123205.1-105602: XRT and UVOT observations of soft short burst source
  77. Short burst found in ground analysis of Swift-BAT data
  78. GRB 150101A Swift-BAT refined analysis of the short hard burst
  79. GRB 150101A: Fermi GBM detection
  80. GRB 150101A: Swift-XRT refined Analysis
  81. GRB 150101A: Swift/UVOT Upper Limits
  82. GRB 150101A: Enhanced Swift-XRT position
  83. GRB 150101A: Swift detection of a short burst
  84. Konus-Wind observation of GRB 141229A
  85. GRB 141229A: Deep MASTER inspection
  86. Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
  87. GRB 141229A Swift-BAT observations
  88. GRB 141230A: iPTF Optical Observations and Candidate Afterglow iPTF14jko
  89. GRB 141229A: Swift-XRT observations
  90. Christmas GRB 141225A: GROND Observations
  91. GRB 141229A Tiled Swift observations
  92. GRB 141225A: MASTER-SAAO OT light curve
  93. GRB 141225A: TAROT Calern observatory optical observations
  94. GRB 141225A: Swift/UVOT refined analysis
  95. GRB 141225A: Fermi GBM detection
  96. GRB 141225A: very early T60 observations
  97. GRB 141225A: Swift-BAT refined analysis
  98. GRB 141225A: Swift-XRT refined Analysis
  99. GRB 141225A: MASTER-SAAO first OT detection
  100. GRB 141225A: Enhanced Swift-XRT position

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