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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"

19607 results found.

  1. GRB 150203A: Fermi GBM observation
  2. GRB 150203A: TAROT La Silla observatory optical observations
  3. GRB 150203A: GROND Upper limits
  4. GRB 150203A: Enhanced Swift-XRT position
  5. GRB 150203A: RATIR Optical and NIR Observations
  6. GRB 150202A: Enhanced Swift-XRT position
  7. GRB 150202A: GROND Upper limits
  8. GRB 150203A: P60 observations
  9. GRB 150203A: KAIT Optical Upper Limit
  10. GRB 150203A: Prompt enhanced Swift-XRT position
  11. GRB 150203A: Swift detection of a burst
  12. GRB 150202A: Swift detection of a burst
  13. GRB 150201A: Swift/UVOT Upper Limits
  14. GRB 150201A, Swift-BAT refined analysis
  15. Konus-Wind observation of GRB 150201A
  16. GRB 150201A: GROND upper limits
  17. GRB 150201A: Swift-XRT refined Analysis
  18. GRB 150201A: Fermi GBM observation
  19. GRB 150201A: Enhanced Swift-XRT position
  20. GRB 150201A: Swift detection of a burst
  21. Swift Trigger 629206 is likely 1RXS J180408.9-342058
  22. GRB 150120B: Khureltogot optical observations
  23. GRB 150123A: MASTER inspection
  24. IPN Triangulation of GRB 150127B
  25. Swift Trigger 628458 likely not astrophysical
  26. GRB 150123A: Swift/UVOT observations
  27. GRB 150123A: Swift-XRT observations
  28. GRB 150120B: Mondy optical observations
  29. GRB 150123A Tiled Swift observations
  30. IPN Triangulation of GRB 150118B (long/intense)
  31. GRB 150120A: ISON-NM early optical limit
  32. GRB 150120B: FTN early optical light curve
  33. GRB 150120B: Swift/UVOT Upper Limits
  34. GRB 150120B, Optical observations
  35. GRB 150120B: GROND Afterglow Detection
  36. GRB 150120A: Swift-XRT refined Analysis
  37. GRB 150120A: KAIT Optical Upper Limit
  38. GRB 150120B: Swift-BAT refined analysis
  39. GRB 150120A: Swift-BAT refined analysis
  40. GRB 150101B/Swift J123205.1-105602: TNG NIR follow-up
  41. GRB 150120B: Swift-XRT refined Analysis
  42. GRB 150120A: Swift/UVOT Upper Limits
  43. GRB 150110B: AMI 15 GHz detection of possible radio counterpart
  44. GRB 150101B/Swift J123205.1-105602, deep VLT observations
  45. GRB 150120B: Enhanced Swift-XRT position
  46. GRB 150120A: Fermi GBM observation
  47. GRB 150101B/Swift J123205.1-105602: XMM-Newton observation
  48. GRB 150120A: Enhanced Swift-XRT position
  49. GRB 150120B: FTN optical afterglow confirmation
  50. GRB 150120B: Swift detection of a burst
  51. GRB 150120A: Prompt enhanced Swift-XRT position
  52. GRB 150120A: Swift detection of a possibly-short burst
  53. GRB 150101B/Swift J123205.1-105602: continued WSRT radio and VLT optical observations
  54. Trigger 626581: Swift detection of GRO J1008-57
  55. GRB 150110B: Khureltogot optical upper limit
  56. The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
  57. Swift detection of the variable star SZ Psc
  58. GRB 150110C: Swift/UVOT Upper Limits
  59. GRB 150110C: Swift-XRT observations
  60. GRB 150110B: Swift-BAT refined analysis
  61. GRB 150110C Tiled Swift observations
  62. GRB 150110B: Swift-XRT refined Analysis
  63. GRB 150110B: Swift/UVOT Upper Limits
  64. GRB 150110B: Fermi GBM Detection
  65. GRB 150110B: Enhanced Swift-XRT position
  66. GRB 150110B: Swift detection of a burst
  67. GRB 150101B/Swift J123205.1-105602: Chandra observations
  68. GRB 150101B / Swift J123205.1-105602: 9.8 GHz VLA observations
  69. GRB 150101B/Swift J123205.1-105602: WSRT radio observation
  70. GRB 150101B / Swift J123205.1-105602: X-ray counterpart is likely an AGN
  71. GRB 150101B/Swift J123205.1-105602: VLT observations and redshift
  72. Swift detection of 4U 1700+24 (= V* V934 Her)
  73. GRB 150103A: MASTER optical observations
  74. GRB 150101B: potential host galaxy redshift by GTC
  75. GRB 150103A: Swift-XRT refined Analysis
  76. GRB 150101B: Fermi GBM detection
  77. GRB 150103A: Swift/UVOT Upper Limits
  78. GRB 150103A: Swift-BAT refined analysis
  79. GRB 150103A: Zadko observatory - Gingin optical observations
  80. GRB 150103A: Enhanced Swift-XRT position
  81. Swift J123205.1-105602: Magellan candidate afterglow
  82. GRB 150103A: Prompt enhanced Swift-XRT position
  83. GRB 150103A: Swift detection of a burst
  84. Swift J123205.1-105602: XRT and UVOT observations of soft short burst source
  85. Short burst found in ground analysis of Swift-BAT data
  86. GRB 150101A Swift-BAT refined analysis of the short hard burst
  87. GRB 150101A: Fermi GBM detection
  88. GRB 150101A: Swift-XRT refined Analysis
  89. GRB 150101A: Swift/UVOT Upper Limits
  90. GRB 150101A: Enhanced Swift-XRT position
  91. GRB 150101A: Swift detection of a short burst
  92. Konus-Wind observation of GRB 141229A
  93. GRB 141229A: Deep MASTER inspection
  94. Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
  95. GRB 141229A Swift-BAT observations
  96. GRB 141230A: iPTF Optical Observations and Candidate Afterglow iPTF14jko
  97. GRB 141229A: Swift-XRT observations
  98. Christmas GRB 141225A: GROND Observations
  99. GRB 141229A Tiled Swift observations
  100. GRB 141225A: MASTER-SAAO OT light curve

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