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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"

41694 results found.

  1. GRB 150110A: MASTER inspection
  2. GRB 150110C Tiled Swift observations
  3. GRB 150110B: Swift-XRT refined Analysis
  4. GRB 150110B: Swift/UVOT Upper Limits
  5. GRB 150110B: Fermi GBM Detection
  6. GRB 150110C: MAXI/GSC detection
  7. GRB 150110A: Fermi GBM Detection
  8. GRB 150110B: Swift detection of a burst
  9. GRB 150110A: MAXI/GSC detection
  10. GRB 150101B/Swift J123205.1-105602: Chandra observations
  11. GRB 150101B / Swift J123205.1-105602: 9.8 GHz VLA observations
  12. Fermi GBM trigger 150108121 is not a GRB
  13. GRB 150101B/Swift J123205.1-105602: WSRT radio observation
  14. GRB 150101B / Swift J123205.1-105602: X-ray counterpart is likely an AGN
  15. Radio upper limit on the GRB 141121A with the GMRT
  16. Fermi GBM trigger 150106207 is not a GRB
  17. GRB 150105A: Fermi GBM detection
  18. GRB 150101B/Swift J123205.1-105602: VLT observations and redshift
  19. Swift detection of 4U 1700+24 (= V* V934 Her)
  20. GRB 150103A: MASTER optical observations
  21. GRB 150103A: Swift-XRT refined Analysis
  22. GRB 150101B: Fermi GBM detection
  23. GRB 150103A: Swift/UVOT Upper Limits
  24. GRB 150103A: Swift-BAT refined analysis
  25. GRB 150103A: Zadko observatory - Gingin optical observations
  26. Swift J123205.1-105602: Magellan candidate afterglow
  27. GRB 150103A: Swift detection of a burst
  28. Swift J123205.1-105602: XRT and UVOT observations of soft short burst source
  29. Short burst found in ground analysis of Swift-BAT data
  30. GRB 150101A Swift-BAT refined analysis of the short hard burst
  31. GRB 150101A: Fermi GBM detection
  32. GRB 150101A: Swift-XRT refined Analysis
  33. GRB 150101A: Swift/UVOT Upper Limits
  34. GRB 150101A: Swift detection of a short burst
  35. Konus-Wind observation of GRB 141229A
  36. GRB 141229A: Deep MASTER inspection
  37. Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
  38. GRB 141230A: Fermi GBM detection
  39. GRB 141229A Swift-BAT observations
  40. GRB 141230A: Nanshan optical obsrvations
  41. GRB 141230A: iPTF Optical Observations and Candidate Afterglow iPTF14jko
  42. GRB 141229A: 1.23m CAHA optical observations
  43. GRB 141229A: Nanshan optical upper limit
  44. GRB 141229A: Swift-XRT observations
  45. Fermi GBM trigger 141229739 is not a GRB
  46. GRB 141229A: Fermi GBM detection
  47. Christmas GRB 141225A: GROND Observations
  48. GRB 141229A Tiled Swift observations
  49. GRB 141229A: MAXI/GSC detection
  50. GRB 141225A: MASTER-SAAO OT light curve
  51. GRB 141225A: MITSuME Okayama upper limits
  52. GRB 141225A: TAROT Calern observatory optical observations
  53. GRB 141225A: Swift/UVOT refined analysis
  54. GRB 141225A: Fermi GBM detection
  55. GRB 141225A: very early T60 observations
  56. GRB 141225A: Swift-BAT refined analysis
  57. GRB 141225A: Swift-XRT refined Analysis
  58. GRB 141225A: MASTER-SAAO first OT detection
  59. GRB 141225A: Nanshan very early optical observations
  60. GRB 141225A: Redshift from OSIRIS at the 10.4m GTC
  61. GRB 141225A: UVOT detection
  62. GRB 141225A: Optical aftergow confirmation
  63. GRB 141225A: LT optical candidate
  64. GRB 141225A: 1.23m CAHA optical observations
  65. GRB 141225A: Swift detection of a burst
  66. GRB 141221A: Keck spectroscopy
  67. GRB 141221A: TAROT La Silla observatory optical observations
  68. Swift XRT and UVOT observations of GRB141222A
  69. Konus-Wind observation of GRB 141222A
  70. GRB 141222A: First MASTER-SAAO optical observation
  71. IPN Triangulation of GRB 141222A (very intense)
  72. GRB 141221A: MITSuME Akeno upper limits
  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 141220A: MITSuME Akeno upper limits
  80. GRB 141221A: Swift-XRT refined Analysis
  81. GRB 141221A: Swift-BAT refined analysis
  82. GRB141221A: GROND Afterglow Detection
  83. GRB 141221A: Skynet PROMPT-CTIO observations of the optical afterglow
  84. GRB 141221A: LCOGT-McDonald optical afterglow observations
  85. GRB141221A: REM afterglow
  86. Konus-Wind observation of GRB 141220A
  87. GRB 141221A: Swift detection of a burst with an optical counterpart
  88. GRB 141220A: Fermi GBM observation
  89. GRB 141220A: MITSuME Okayama upper limits
  90. GRB 141220A: Swift-XRT refined Analysis
  91. GRB 141220A: Swift-BAT refined analysis
  92. GRB 141220A: Swift/UVOT Detection
  93. GRB 141220A: Photometry from OSIRIS/GTC
  94. GRB 141220A: LT optical afterglow observations
  95. GRB 141220A: Redshift from OSIRIS at the 10.4m GTC
  96. GRB141220A: 1.23m CAHA I-band observations
  97. GRB 141220A: Swift detection of a burst with an optical afterglow
  98. Fermi Gamma-ray Burst Monitor trigger 440728127 / 141220020 is not a GRB
  99. IPN Triangulation of GRB 141207A
  100. GRB 141207A: Suzaku WAM observation of the prompt emission

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