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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"

37517 results found.

  1. GRB 150110C: Swift/UVOT Upper Limits
  2. GRB 150110C: Swift-XRT observations
  3. GRB 150110B: Swift-BAT refined analysis
  4. GRB 150110A: MASTER inspection
  5. GRB 150110C Tiled Swift observations
  6. GRB 150110B: Swift-XRT refined Analysis
  7. GRB 150110B: Swift/UVOT Upper Limits
  8. GRB 150110B: Fermi GBM Detection
  9. GRB 150110B: Enhanced Swift-XRT position
  10. GRB 150110C: MAXI/GSC detection
  11. GRB 150110A: Fermi GBM Detection
  12. GRB 150110B: Swift detection of a burst
  13. GRB 150110A: MAXI/GSC detection
  14. GRB 150101B/Swift J123205.1-105602: Chandra observations
  15. GRB 150101B / Swift J123205.1-105602: 9.8 GHz VLA observations
  16. Fermi GBM trigger 150108121 is not a GRB
  17. GRB 150101B/Swift J123205.1-105602: WSRT radio observation
  18. GRB 150101B / Swift J123205.1-105602: X-ray counterpart is likely an AGN
  19. Radio upper limit on the GRB 141121A with the GMRT
  20. Fermi GBM trigger 150106207 is not a GRB
  21. GRB 150105A: Fermi GBM detection
  22. GRB 150101B/Swift J123205.1-105602: VLT observations and redshift
  23. GRB 150103A: MASTER optical observations
  24. GRB 150101B: potential host galaxy redshift by GTC
  25. GRB 150103A: Swift-XRT refined Analysis
  26. GRB 150101B: Fermi GBM detection
  27. GRB 150103A: Swift/UVOT Upper Limits
  28. GRB 150103A: Swift-BAT refined analysis
  29. GRB 150103A: Zadko observatory - Gingin optical observations
  30. GRB 150103A: Enhanced Swift-XRT position
  31. Swift J123205.1-105602: Magellan candidate afterglow
  32. GRB 150103A: Prompt enhanced Swift-XRT position
  33. GRB 150103A: Swift detection of a burst
  34. Short burst found in ground analysis of Swift-BAT data
  35. GRB 150101A Swift-BAT refined analysis of the short hard burst
  36. GRB 150101A: Fermi GBM detection
  37. GRB 150101A: Swift-XRT refined Analysis
  38. GRB 150101A: Swift/UVOT Upper Limits
  39. GRB 150101A: Enhanced Swift-XRT position
  40. GRB 150101A: Swift detection of a short burst
  41. Konus-Wind observation of GRB 141229A
  42. GRB 141229A: Deep MASTER inspection
  43. Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
  44. GRB 141230A: Fermi GBM detection
  45. GRB 141229A Swift-BAT observations
  46. GRB 141230A: Nanshan optical obsrvations
  47. GRB 141230A: iPTF Optical Observations and Candidate Afterglow iPTF14jko
  48. GRB 141229A: 1.23m CAHA optical observations
  49. GRB 141229A: Nanshan optical upper limit
  50. GRB 141229A: Swift-XRT observations
  51. Fermi GBM trigger 141229739 is not a GRB
  52. GRB 141229A: Fermi GBM detection
  53. Christmas GRB 141225A: GROND Observations
  54. GRB 141229A Tiled Swift observations
  55. GRB 141229A: MAXI/GSC detection
  56. GRB 141225A: MASTER-SAAO OT light curve
  57. GRB 141225A: MITSuME Okayama upper limits
  58. GRB 141225A: TAROT Calern observatory optical observations
  59. GRB 141225A: Swift/UVOT refined analysis
  60. GRB 141225A: Fermi GBM detection
  61. GRB 141225A: very early T60 observations
  62. GRB 141225A: Swift-BAT refined analysis
  63. GRB 141225A: Swift-XRT refined Analysis
  64. GRB 141225A: MASTER-SAAO first OT detection
  65. GRB 141225A: Nanshan very early optical observations
  66. GRB 141225A: Enhanced Swift-XRT position
  67. GRB 141225A: Redshift from OSIRIS at the 10.4m GTC
  68. GRB 141225A: UVOT detection
  69. GRB 141225A: Optical aftergow confirmation
  70. GRB 141225A: LT optical candidate
  71. GRB 141225A: 1.23m CAHA optical observations
  72. GRB 141225A: Swift detection of a burst
  73. GRB 141221A: Keck spectroscopy
  74. GRB 141221A: TAROT La Silla observatory optical observations
  75. Swift XRT and UVOT observations of GRB141222A
  76. Konus-Wind observation of GRB 141222A
  77. GRB 141222A: First MASTER-SAAO optical observation
  78. IPN Triangulation of GRB 141222A (very intense)
  79. GRB 141221A: MITSuME Akeno upper limits
  80. GRB 141221A: Continued Skynet PROMPT-CTIO observations
  81. GRB 141222A: Fermi GBM detection
  82. GRB 141221A: Swift/UVOT Detection
  83. GRB 141222A: Fermi-LAT detection
  84. GRB 141215A: further Swift-XRT observations and afterglow detection
  85. GRB 141221A: Fermi GBM observation
  86. GRB 141220A: MITSuME Akeno upper limits
  87. GRB 141221A: Swift-XRT refined Analysis
  88. GRB 141221A: Swift-BAT refined analysis
  89. GRB141221A: GROND Afterglow Detection
  90. GRB 141221A: Enhanced Swift-XRT position
  91. GRB 141221A: Skynet PROMPT-CTIO observations of the optical afterglow
  92. GRB 141221A: LCOGT-McDonald optical afterglow observations
  93. GRB141221A: REM afterglow
  94. Konus-Wind observation of GRB 141220A
  95. GRB 141221A: Swift detection of a burst with an optical counterpart
  96. GRB 141220A: Fermi GBM observation
  97. GRB 141220A: MITSuME Okayama upper limits
  98. GRB 141220A: Swift-XRT refined Analysis
  99. GRB 141220A: Swift-BAT refined analysis
  100. GRB 141220A: Swift/UVOT Detection

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