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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"

19548 results found.

  1. GRB 150120B: Enhanced Swift-XRT position
  2. GRB 150101B/Swift J123205.1-105602: XMM-Newton observation
  3. GRB 150120A: Enhanced Swift-XRT position
  4. GRB 150120B: P60 optical afterglow
  5. GRB 150120B: Swift detection of a burst
  6. GRB 150120A: Gemini-North optical imaging
  7. GRB 150120A: Swift detection of a possibly-short burst
  8. GRB 150101B/Swift J123205.1-105602: continued WSRT radio and VLT optical observations
  9. GRB 150118B: Fermi GBM Detection
  10. GRB 150118B: Fermi-LAT detection
  11. GRB 150110B: Khureltogot optical upper limit
  12. The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
  13. Swift detection of the variable star SZ Psc
  14. GRB 150110C: Swift/UVOT Upper Limits
  15. GRB 150110B: Swift-BAT refined analysis
  16. GRB 150110B: Swift/UVOT Upper Limits
  17. GRB 150110B: Fermi GBM Detection
  18. GRB 150110B: Enhanced Swift-XRT position
  19. GRB 150110A: Fermi GBM Detection
  20. GRB 150110B: Swift detection of a burst
  21. GRB 150101B/Swift J123205.1-105602: Chandra observations
  22. GRB 150101B / Swift J123205.1-105602: 9.8 GHz VLA observations
  23. Fermi GBM trigger 150108121 is not a GRB
  24. Swift detection of 4U 1700+24 (= V* V934 Her)
  25. GRB 150101B: Fermi GBM detection
  26. GRB 150103A: Swift/UVOT Upper Limits
  27. GRB 150103A: Zadko observatory - Gingin optical observations
  28. GRB 150103A: Enhanced Swift-XRT position
  29. GRB 150103A: Swift detection of a burst
  30. Swift J123205.1-105602: XRT and UVOT observations of soft short burst source
  31. Short burst found in ground analysis of Swift-BAT data
  32. GRB 150101A: Swift/UVOT Upper Limits
  33. GRB 150101A: Enhanced Swift-XRT position
  34. GRB 150101A: Swift detection of a short burst
  35. Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
  36. GRB 141229A Swift-BAT observations
  37. GRB 141230A: Nanshan optical obsrvations
  38. GRB 141229A: 1.23m CAHA optical observations
  39. GRB 141229A: Nanshan optical upper limit
  40. Christmas GRB 141225A: GROND Observations
  41. GRB 141225A: MITSuME Okayama upper limits
  42. GRB 141225A: TAROT Calern observatory optical observations
  43. GRB 141225A: Swift/UVOT refined analysis
  44. GRB 141225A: very early T60 observations
  45. GRB 141225A: Swift-BAT refined analysis
  46. GRB 141225A: Nanshan very early optical observations
  47. GRB 141225A: Enhanced Swift-XRT position
  48. GRB 141225A: Optical aftergow confirmation
  49. GRB 141225A: 1.23m CAHA optical observations
  50. GRB 141225A: Swift detection of a burst
  51. GRB 141221A: TAROT La Silla observatory optical observations
  52. Swift XRT and UVOT observations of GRB141222A
  53. GRB 141221A: MITSuME Akeno upper limits
  54. GRB 141221A: Continued Skynet PROMPT-CTIO observations
  55. GRB 141221A: Swift/UVOT Detection
  56. GRB 141215A: further Swift-XRT observations and afterglow detection
  57. GRB 141221A: Fermi GBM observation
  58. GRB 141220A: MITSuME Akeno upper limits
  59. GRB 141221A: Swift-XRT refined Analysis
  60. GRB141221A: GROND Afterglow Detection
  61. GRB 141221A: Enhanced Swift-XRT position
  62. GRB 141221A: Skynet PROMPT-CTIO observations of the optical afterglow
  63. GRB141221A: REM afterglow
  64. GRB 141221A: Swift detection of a burst with an optical counterpart
  65. GRB 141220A: Fermi GBM observation
  66. GRB 141220A: MITSuME Okayama upper limits
  67. GRB 141220A: Swift-XRT refined Analysis
  68. GRB 141220A: Swift/UVOT Detection
  69. GRB141220A: 1.23m CAHA I-band observations
  70. GRB 141220A: Swift detection of a burst with an optical afterglow
  71. IPN Triangulation of GRB 141215A (long/intense)
  72. GRB 141212A iTelescope observation
  73. GRB 141212A: Zadko observatory - Gingin optical observations
  74. GRB 141212B: MITSuME Akeno upper limits
  75. GRB 141212A: Swift/UVOT Upper Limits
  76. GRB 141212B: Swift/UVOT Upper Limits
  77. GRB 141212A: VLA upper limit
  78. GRB 141212A: Gemini-N spectroscopy and photometry
  79. GRB 141212B: Enhanced Swift-XRT position
  80. Swift detection of 4U 1700+24 (= V934 Her)
  81. GRB 141212A: MITSuME Okayama upper limits
  82. GRB 141212A: extended object within the XRT error circle
  83. GRB 141212A: Khureltogot optical upper limit
  84. GRB 141212A: 1.23m CAHA I-band observations
  85. GRB 141212B: initial Swift/UVOT observations
  86. GRB 141212A: Enhanced Swift-XRT position
  87. GRB 141212A: Skynet R-COP Observations
  88. GRB 141212A: MITSuME Akeno upper limits
  89. GRB 141212B: Swift detection of a burst
  90. GRB 141212A: Swift detection of a short burst
  91. GRB 141207A: Swift-XRT afterglow candidate detection
  92. GRB141202A: Discovery Channel Telescope Optical Observations
  93. GRB141207A: Discovery Channel Telescope Optical Observations
  94. GRB 141207A: Swift-XRT observations
  95. GRB141121A: Discovery Channel Telescope Optical Observations
  96. GRB 141205A: Swift/UVOT Upper Limits
  97. GRB 141205A: Nanshan optical upper limit
  98. GRB 141121A: Mondy optical observations
  99. GRB 141130A: Mondy optical observations
  100. GRB 141030A: Nanshan very early optical observations

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