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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"

19595 results found.

  1. GRB 150201A: GROND upper limits
  2. GRB 150201A: Swift-XRT refined Analysis
  3. GRB 150201A: Fermi GBM observation
  4. GRB 150201A: Enhanced Swift-XRT position
  5. GRB 150201A: Swift detection of a burst
  6. Swift Trigger 629206 is likely 1RXS J180408.9-342058
  7. GRB 150120B: Khureltogot optical observations
  8. GRB 150123A: MASTER inspection
  9. IPN Triangulation of GRB 150127B
  10. Swift Trigger 628458 likely not astrophysical
  11. GRB 150123A: Swift/UVOT observations
  12. GRB 150123A: Swift-XRT observations
  13. GRB 150120B: Mondy optical observations
  14. GRB 150123A Tiled Swift observations
  15. IPN Triangulation of GRB 150118B (long/intense)
  16. GRB 150120A: ISON-NM early optical limit
  17. GRB 150120B: FTN early optical light curve
  18. GRB 150120B: Swift/UVOT Upper Limits
  19. GRB 150120B, Optical observations
  20. GRB 150120B: GROND Afterglow Detection
  21. GRB 150120A: Swift-XRT refined Analysis
  22. GRB 150120A: KAIT Optical Upper Limit
  23. GRB 150120B: Swift-BAT refined analysis
  24. GRB 150120A: Swift-BAT refined analysis
  25. GRB 150101B/Swift J123205.1-105602: TNG NIR follow-up
  26. GRB 150120B: Swift-XRT refined Analysis
  27. GRB 150120A: Swift/UVOT Upper Limits
  28. GRB 150110B: AMI 15 GHz detection of possible radio counterpart
  29. GRB 150101B/Swift J123205.1-105602, deep VLT observations
  30. GRB 150120B: Enhanced Swift-XRT position
  31. GRB 150120A: Fermi GBM observation
  32. GRB 150101B/Swift J123205.1-105602: XMM-Newton observation
  33. GRB 150120A: Enhanced Swift-XRT position
  34. GRB 150120B: FTN optical afterglow confirmation
  35. GRB 150120B: Swift detection of a burst
  36. GRB 150120A: Prompt enhanced Swift-XRT position
  37. GRB 150120A: Swift detection of a possibly-short burst
  38. GRB 150101B/Swift J123205.1-105602: continued WSRT radio and VLT optical observations
  39. Trigger 626581: Swift detection of GRO J1008-57
  40. GRB 150110B: Khureltogot optical upper limit
  41. The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
  42. Swift detection of the variable star SZ Psc
  43. GRB 150110C: Swift/UVOT Upper Limits
  44. GRB 150110C: Swift-XRT observations
  45. GRB 150110B: Swift-BAT refined analysis
  46. GRB 150110C Tiled Swift observations
  47. GRB 150110B: Swift-XRT refined Analysis
  48. GRB 150110B: Swift/UVOT Upper Limits
  49. GRB 150110B: Fermi GBM Detection
  50. GRB 150110B: Enhanced Swift-XRT position
  51. GRB 150110B: Swift detection of a burst
  52. GRB 150101B/Swift J123205.1-105602: Chandra observations
  53. GRB 150101B / Swift J123205.1-105602: 9.8 GHz VLA observations
  54. GRB 150101B/Swift J123205.1-105602: WSRT radio observation
  55. GRB 150101B / Swift J123205.1-105602: X-ray counterpart is likely an AGN
  56. GRB 150101B/Swift J123205.1-105602: VLT observations and redshift
  57. Swift detection of 4U 1700+24 (= V* V934 Her)
  58. GRB 150103A: MASTER optical observations
  59. GRB 150101B: potential host galaxy redshift by GTC
  60. GRB 150103A: Swift-XRT refined Analysis
  61. GRB 150101B: Fermi GBM detection
  62. GRB 150103A: Swift/UVOT Upper Limits
  63. GRB 150103A: Swift-BAT refined analysis
  64. GRB 150103A: Zadko observatory - Gingin optical observations
  65. GRB 150103A: Enhanced Swift-XRT position
  66. Swift J123205.1-105602: Magellan candidate afterglow
  67. GRB 150103A: Prompt enhanced Swift-XRT position
  68. GRB 150103A: Swift detection of a burst
  69. Swift J123205.1-105602: XRT and UVOT observations of soft short burst source
  70. Short burst found in ground analysis of Swift-BAT data
  71. GRB 150101A Swift-BAT refined analysis of the short hard burst
  72. GRB 150101A: Fermi GBM detection
  73. GRB 150101A: Swift-XRT refined Analysis
  74. GRB 150101A: Swift/UVOT Upper Limits
  75. GRB 150101A: Enhanced Swift-XRT position
  76. GRB 150101A: Swift detection of a short burst
  77. Konus-Wind observation of GRB 141229A
  78. GRB 141229A: Deep MASTER inspection
  79. Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
  80. GRB 141229A Swift-BAT observations
  81. GRB 141230A: iPTF Optical Observations and Candidate Afterglow iPTF14jko
  82. GRB 141229A: Swift-XRT observations
  83. Christmas GRB 141225A: GROND Observations
  84. GRB 141229A Tiled Swift observations
  85. GRB 141225A: MASTER-SAAO OT light curve
  86. GRB 141225A: TAROT Calern observatory optical observations
  87. GRB 141225A: Swift/UVOT refined analysis
  88. GRB 141225A: Fermi GBM detection
  89. GRB 141225A: very early T60 observations
  90. GRB 141225A: Swift-BAT refined analysis
  91. GRB 141225A: Swift-XRT refined Analysis
  92. GRB 141225A: MASTER-SAAO first OT detection
  93. GRB 141225A: Enhanced Swift-XRT position
  94. GRB 141225A: UVOT detection
  95. GRB 141225A: LT optical candidate
  96. GRB 141225A: Swift detection of a burst
  97. GRB 141221A: TAROT La Silla observatory optical observations
  98. Swift XRT and UVOT observations of GRB141222A
  99. GRB 141221A: Continued Skynet PROMPT-CTIO observations
  100. GRB 141221A: Swift/UVOT Detection

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