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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"

27408 results found.

  1. GRB 150120A: Swift/UVOT Upper Limits
  2. GRB 150101B/Swift J123205.1-105602, deep VLT observations
  3. GRB 150120A: Fermi GBM observation
  4. GRB 150120B: FTN optical afterglow confirmation
  5. GRB 150120B: Swift detection of a burst
  6. GRB 150120A: Gemini-North optical imaging
  7. GRB 150120A: P60 optical observations
  8. GRB 150120A: Swift detection of a possibly-short burst
  9. GRB 150101B/Swift J123205.1-105602: continued WSRT radio and VLT optical observations
  10. GRB 150118B: Fermi GBM Detection
  11. GRB 150118B: Fermi-LAT detection
  12. Trigger 626581: Swift detection of GRO J1008-57
  13. The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
  14. Swift detection of the variable star SZ Psc
  15. GRB 150110C: Swift/UVOT Upper Limits
  16. GRB 150110C: Swift-XRT observations
  17. GRB 150110B: Swift-BAT refined analysis
  18. GRB 150110A: MASTER inspection
  19. GRB 150110B: Swift-XRT refined Analysis
  20. GRB 150110B: Swift/UVOT Upper Limits
  21. GRB 150110B: Fermi GBM Detection
  22. GRB 150110A: Fermi GBM Detection
  23. GRB 150110B: Swift detection of a burst
  24. GRB 150101B / Swift J123205.1-105602: 9.8 GHz VLA observations
  25. Fermi GBM trigger 150108121 is not a GRB
  26. GRB 150101B/Swift J123205.1-105602: WSRT radio observation
  27. Fermi GBM trigger 150106207 is not a GRB
  28. GRB 150105A: Fermi GBM detection
  29. GRB 150101B/Swift J123205.1-105602: VLT observations and redshift
  30. Swift detection of 4U 1700+24 (= V* V934 Her)
  31. GRB 150103A: MASTER optical observations
  32. GRB 150101B: potential host galaxy redshift by GTC
  33. GRB 150103A: Swift-XRT refined Analysis
  34. GRB 150101B: Fermi GBM detection
  35. GRB 150103A: Swift/UVOT Upper Limits
  36. GRB 150103A: Swift-BAT refined analysis
  37. GRB 150103A: Zadko observatory - Gingin optical observations
  38. Swift J123205.1-105602: Magellan candidate afterglow
  39. GRB 150103A: Swift detection of a burst
  40. Swift J123205.1-105602: XRT and UVOT observations of soft short burst source
  41. Short burst found in ground analysis of Swift-BAT data
  42. GRB 150101A Swift-BAT refined analysis of the short hard burst
  43. GRB 150101A: Fermi GBM detection
  44. GRB 150101A: Swift-XRT refined Analysis
  45. GRB 150101A: Swift/UVOT Upper Limits
  46. GRB 150101A: Swift detection of a short burst
  47. Konus-Wind observation of GRB 141229A
  48. GRB 141229A: Deep MASTER inspection
  49. Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
  50. GRB 141230A: Fermi GBM detection
  51. GRB 141229A Swift-BAT observations
  52. GRB 141230A: Nanshan optical obsrvations
  53. GRB 141230A: iPTF Optical Observations and Candidate Afterglow iPTF14jko
  54. GRB 141229A: Swift-XRT observations
  55. Fermi GBM trigger 141229739 is not a GRB
  56. GRB 141229A: Fermi GBM detection
  57. Christmas GRB 141225A: GROND Observations
  58. GRB 141225A: MASTER-SAAO OT light curve
  59. GRB 141225A: TAROT Calern observatory optical observations
  60. GRB 141225A: Swift/UVOT refined analysis
  61. GRB 141225A: Fermi GBM detection
  62. GRB 141225A: very early T60 observations
  63. GRB 141225A: Swift-BAT refined analysis
  64. GRB 141225A: Swift-XRT refined Analysis
  65. GRB 141225A: MASTER-SAAO first OT detection
  66. GRB 141225A: UVOT detection
  67. GRB 141225A: Optical aftergow confirmation
  68. GRB 141225A: LT optical candidate
  69. GRB 141225A: Swift detection of a burst
  70. GRB 141221A: TAROT La Silla observatory optical observations
  71. Swift XRT and UVOT observations of GRB141222A
  72. GRB 141222A: First MASTER-SAAO optical observation
  73. GRB 141221A: Continued Skynet PROMPT-CTIO observations
  74. GRB 141222A: Fermi GBM detection
  75. GRB 141221A: Swift/UVOT Detection
  76. GRB 141222A: Fermi-LAT detection
  77. GRB 141215A: further Swift-XRT observations and afterglow detection
  78. GRB 141221A: Fermi GBM observation
  79. GRB 141221A: Swift-XRT refined Analysis
  80. GRB 141221A: Swift-BAT refined analysis
  81. GRB141221A: GROND Afterglow Detection
  82. GRB 141221A: Skynet PROMPT-CTIO observations of the optical afterglow
  83. GRB 141221A: LCOGT-McDonald optical afterglow observations
  84. Konus-Wind observation of GRB 141220A
  85. GRB 141221A: Swift detection of a burst with an optical counterpart
  86. GRB 141220A: Fermi GBM observation
  87. GRB 141220A: Swift-XRT refined Analysis
  88. GRB 141220A: Swift-BAT refined analysis
  89. GRB 141220A: Swift/UVOT Detection
  90. GRB 141220A: LT optical afterglow observations
  91. GRB 141220A: Swift detection of a burst with an optical afterglow
  92. Fermi Gamma-ray Burst Monitor trigger 440728127 / 141220020 is not a GRB
  93. IPN Triangulation of GRB 141207A
  94. GRB 141215A: Swift-XRT observations
  95. GRB 141215A: Fermi GBM detection
  96. IPN Triangulation of GRB 141215A (long/intense)
  97. GRB 141212A iTelescope observation
  98. GRB 141212A: Zadko observatory - Gingin optical observations
  99. Konus-Wind observation of GRB 141212B
  100. GRB 141212B: Swift-XRT refined Analysis

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