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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"

850 results found.

  1. GRB 150801A: Tiled Swift observations
  2. GRB 150801A: MAXI/GSC detection
  3. GRB 150727A: Swift/UVOT Detection
  4. Konus-Wind observation of GRB 150725A
  5. GRB 150725A: MAXI/GSC detection
  6. GRB 150622A: Swift-XRT afterglow detection
  7. V404 Cyg activity (Swift, Fermi, INTGRAL, KONUS, MAXI detection): optical observations in TSHAO, Khureltogot, and AAO
  8. GRB 150627A: Swift/UVOT Detection
  9. GRB 150622A: Swift-XRT observations
  10. GRB 150622A: Tiled Swift observations
  11. GRB 150622A: MAXI/GSC detection
  12. GRB 150608A: Swift-XRT follow-up observations
  13. Konus-Wind observation of GRB 150608A
  14. GRB 150608A: Swift-XRT afterglow detection
  15. GRB 150608A: Tiled Swift observations
  16. GRB 150608A: MAXI/GSC detection
  17. GRB 150518A: possible SN observations
  18. GRB 150518A: MAXI-GSC further analysis
  19. GRB 150518A: Mondy optical observations
  20. GRB 150518A: AMI 15 GHz detection of possible radio counterpart
  21. GRB 150518A: MASTER-net before, early and after optical stereoscopic observations with possible MP discovery inside MAXI error box
  22. Konus-Wind observation of GRB 150518A
  23. GRB 150518A: Swift-XRT follow-up observations
  24. GRB 150518A: Correction
  25. GRB 150518A: VLT/X-shooter redshift of the likely host galaxy
  26. Swift/UVOT observations of GRB150518A
  27. GRB 150518A: Swift-XRT afterglow detection
  28. GRB 150518A: Tiled Swift observations
  29. GRB 150518A: MAXI/GSC detection
  30. Konus-Wind observation of GRB 150430A
  31. GRB 150430A: Fermi GBM Detection
  32. GRB 150430A: MAXI/GSC detection
  33. GRB 150428C: Swift-XRT observations
  34. GRB 150428C: Tiled Swift observations
  35. GRB 150428C/MAXI J0400+678: MAXI/GSC detection
  36. GRB 150424B: Fermi GBM detection
  37. GRB 150424B: Tiled Swift observations
  38. GRB 150424B: MAXI/GSC detection
  39. Konus-Wind observation of GRB 150418A
  40. GRB150418A: Swift/UVOT did not detect a new source
  41. GRB 150418A: Swift-XRT observations
  42. GRB 150418A: Tiled Swift observations
  43. GRB 150418A: MAXI/GSC detection
  44. GRB 150413A: MAXI/GSC detection
  45. GRB 150403A: Swift/UVOT Detection
  46. GRB 150313A: MAXI/GSC detection
  47. GRB 150311A: Konus-Wind trigger at 16:16:24 is not a GRB
  48. GRB 150311A: MAXI/GSC possible afterglow detection
  49. GRB 150301B: Swift/UVOT Observations
  50. GRB 150222B: MAXI/GSC detection
  51. Konus-Wind observation of GRB 150206A
  52. Trigger 630047: Swift detection of 1RXS J180408.9-342058
  53. GRB 150206A: MAXI/GSC detection
  54. GRB 150123A: MASTER inspection
  55. Konus-Wind observation of GRB 150126A reveals its ultra-long nature
  56. GRB 150126A: Fermi GBM Detection
  57. GRB 150126A: MAXI/GSC afterglow candidate detection
  58. Konus-Wind observation of GRB 150123A
  59. GRB 150123A: Swift/UVOT observations
  60. GRB 150123A: Swift-XRT observations
  61. GRB 150123A Tiled Swift observations
  62. GRB 150123A: MAXI/GSC detection
  63. The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
  64. GRB 150110C: Swift/UVOT Upper Limits
  65. GRB 150110C: Swift-XRT observations
  66. GRB 150110A: MASTER inspection
  67. GRB 150110C Tiled Swift observations
  68. GRB 150110C: MAXI/GSC detection
  69. GRB 150110A: Fermi GBM Detection
  70. GRB 150110A: MAXI/GSC detection
  71. Konus-Wind observation of GRB 141229A
  72. GRB 141229A: Deep MASTER inspection
  73. GRB 141229A: Nanshan optical upper limit
  74. GRB 141229A: Swift-XRT observations
  75. GRB 141229A: Fermi GBM detection
  76. GRB 141229A: MAXI/GSC detection
  77. GRB 141121A: SPI-ACS/INTEGRAL observations
  78. Konus-Wind observation of GRB 141121A
  79. GRB 141121A: MAXI/GSC detection
  80. MAXI GRB 141029A is likely an X-ray flare from 1RXS J043657.1-161258
  81. GRB 141029A: Nanshan optical upper limit
  82. GRB 141029A Tiled Swift observations
  83. GRB 141029A: MAXI/GSC detection
  84. GRB 141020B: MAXI/GSC detection
  85. GRB 140930A/MAXI J2259+524: MASTER optical observations
  86. GRB 140928A: MAXI-GSC detection
  87. GRB 140930A/MAXI J2259+524: MAXI-GSC detection
  88. GRB 140903A: MAXI/GSC upper limit
  89. GRB 140818A: GROND confirmation of afterglow candidate
  90. Konus-Wind observation of GRB 140818A
  91. GRB 140818A - Fermi GBM Detection
  92. GRB 140818A: Swift-XRT and UVOT potential afterglow detection
  93. GRB 140818A: Correction to GCN 16702
  94. GRB 140818A Tiled Swift observations
  95. GRB 140818A: MAXI/GSC detection
  96. GRB 140814A: Swift-XRT and UVOT observations
  97. GRB 140814A: MASTER optical follow-up inspection
  98. GRB 140814A: Swift-XRT and UVOT observations
  99. GRB 140814A: MAXI/GSC detection
  100. Swift observations of a flare from UX Ari

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