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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"

12321 results found.

  1. GRB 150301A: Swift/UVOT Upper Limits
  2. GRB 150301B: MASTER early OT detection
  3. GRB 150301C : (Swift trigger 633105) Swift observations
  4. Swift Trigger 633173 is probably not an astrophysical source
  5. Trigger 633105 is likely not a GRB
  6. Trigger 632888: Swift detection of the magnetar 4U 0142+61
  7. GRB 150220A: Swift-XRT observations
  8. Konus-Wind observation of GRB 150220A
  9. GRB 150222A: Swift/UVOT Upper Limits
  10. GRB 150222B: MAXI/GSC detection
  11. GRB 150222A: MASTER early optical observations
  12. GRB 150222A: Swift detection of a burst
  13. Swift detection of an outburst from SGR 1935+2154
  14. Trigger 631747: Swift detection of 4U 0614+09
  15. GRB 150213B: Swift/UVOT Detection
  16. GRB 150213B: RATIR Optical and NIR Observations
  17. GRB 150211A: ROTSE-III Upper Optical Limit
  18. GRB 150212A: RATIR Optical and NIR Observations
  19. GRB 150212A: Khureltogot optical upper limit
  20. GRB 150212A: MASTER optical observations
  21. GRB 150210A: Swift-XRT observations
  22. GRB 150211A iTelescope observation
  23. GRB 150211A: Swift/UVOT Upper Limits
  24. GRB 150210A: MASTER SN detection during LAT error box inspection
  25. GRB 150211A: KAIT Optical Upper Limit
  26. GRB 150211A: Mondy optical upper limit
  27. Konus-Wind observation of GRB 150210A
  28. GRB 150211A: RATIR Optical and NIR Observations
  29. GRB 150211A: No afterglow detection in the Swift/UVOT initial observation
  30. GRB 150211A: MASTER early optical observations
  31. GRB 150204A: GROND observations
  32. GRB 150202B: Swift/XRT afterglow confirmation
  33. GRB 150204A: Swift/XRT afterglow confirmation
  34. GRB 150203A iTelescope observation
  35. GRB 150206A: Swift/UVOT Detection
  36. GRB 150206A: GROND afterglow observations
  37. GRB 150206A: MAXI/GSC detection
  38. GRB 150204A: Swift/UVOT Upper Limits
  39. GRB 150204A: Swift-XRT observations
  40. GRB 150202B: Swift XRT/UVOT observations
  41. Swift Trigger 629693 was a noise event
  42. GRB 150203A: Swift/UVOT Upper Limits
  43. GRB 150203A: MITSuME Okayama upper limits
  44. Swift Trigger 629693: probably not real
  45. GRB 150202A: Swift/UVOT Upper Limits
  46. GRB 150203A: REM optical and NIR observations
  47. GRB 150203A: GROND Upper limits
  48. GRB 150203A: RATIR Optical and NIR Observations
  49. GRB 150202A: GROND Upper limits
  50. GRB 150203A: KAIT Optical Upper Limit
  51. GRB 150203A: Swift detection of a burst
  52. GRB 150202A: Swift detection of a burst
  53. GRB 150201A: Swift/UVOT Upper Limits
  54. GRB 150201A: GROND upper limits
  55. GRB 150201A: Swift detection of a burst
  56. GRB 150128A: MASTER OT detction during inspection
  57. Konus-Wind observation of GRB 150127B
  58. GRB 150123A: MASTER inspection
  59. GRB 150120A: 9.8 GHz VLA upper limit
  60. Konus-Wind observation of GRB 150126A reveals its ultra-long nature
  61. Swift Trigger 628458 likely not astrophysical
  62. GRB 150126A: MAXI/GSC afterglow candidate detection
  63. GRB 150120A: possible AMI 15 GHz detection
  64. GRB 150123A: Swift/UVOT observations
  65. GRB 150123A: MAXI/GSC detection
  66. Konus-Wind observation of GRB 150118B
  67. GRB 150120B: RATIR Optical and NIR Observations
  68. GRB 150120B: Swift/UVOT Upper Limits
  69. GRB 150120B: GROND Afterglow Detection
  70. GRB 150120A: KAIT Optical Upper Limit
  71. GRB 150120B: MITSuME Okayama upper limits
  72. Konus-Wind observation of GRB 150118C
  73. GRB 150120A: Swift/UVOT Upper Limits
  74. GRB 150110B: AMI 15 GHz detection of possible radio counterpart
  75. GRB 150120A: Swift detection of a possibly-short burst
  76. GRB 150110B: Khureltogot optical upper limit
  77. GRB 150110C: Swift/UVOT Upper Limits
  78. GRB 150110A: MASTER inspection
  79. GRB 150110B: Swift/UVOT Upper Limits
  80. GRB 150110C: MAXI/GSC detection
  81. GRB 150110B: Swift detection of a burst
  82. GRB 150110A: MAXI/GSC detection
  83. Radio upper limit on the GRB 141121A with the GMRT
  84. GRB 150103A: MASTER optical observations
  85. GRB 150103A: Swift/UVOT Upper Limits
  86. GRB 150103A: Swift detection of a burst
  87. GRB 150101A: Swift/UVOT Upper Limits
  88. GRB 150101A: Swift detection of a short burst
  89. Konus-Wind observation of GRB 141229A
  90. GRB 141229A: Deep MASTER inspection
  91. Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
  92. GRB 141229A: Nanshan optical upper limit
  93. GRB 141225A: MITSuME Okayama upper limits
  94. GRB 141225A: Swift/UVOT refined analysis
  95. Swift XRT and UVOT observations of GRB141222A
  96. Konus-Wind observation of GRB 141222A
  97. GRB 141221A: MITSuME Akeno upper limits
  98. GRB 141221A: Swift/UVOT Detection
  99. GRB 141215A: further Swift-XRT observations and afterglow detection
  100. GRB 141220A: MITSuME Akeno upper limits

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