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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.

"200205A/SWIFT J0840.7-3516" does not adhere to advanced search syntax. Please refer to the documentation and try again.
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"

19607 results found.

  1. GRB 191031D: RATIR Optical and NIR Observations
  2. GRB 191031C: Fermi GBM detection
  3. GRB 191031D: Fermi GBM detection
  4. GRB 191031D: Enhanced Swift-XRT position
  5. GRB 191031A: Fermi GBM detection
  6. GRB 191031C: Enhanced Swift-XRT position
  7. Swift GRB191031.89: Global MASTER-Net observations report
  8. GRB 191031D: Swift detection of a short hard burst
  9. GRB 191029A: Swift-BAT refined analysis
  10. GRB 191031C: Prompt enhanced Swift-XRT position
  11. GRB 191031C: Swift detection of a burst
  12. GRB 191031A: Swift detection of a burst
  13. GRB 191029A: CORRECTED Swift-XRT refined analysis
  14. GRB 191029A: Swift/UVOT Upper Limits
  15. GRB 191029A: Enhanced Swift-XRT position
  16. GRB 191029A: Swift-XRT refined Analysis
  17. GRB 191029A: BOOTES-4/MET optical limit
  18. GRB 191029A: Swift-XRT observations
  19. GRB 191029A: Swift detection of a burst
  20. IPN triangulation of GRB 191027A
  21. Swift/BAT Trigger 931384 is not a GRB ( 191025A )
  22. Swift Trigger 931484 is not a GRB
  23. Possible GRB 191025A: FRAM-Auger optical limit
  24. Swift Trigger 931384: possible GRB 191025A
  25. GRB 191024A: Swift-BAT refined analysis
  26. GRB 191024A: Swift/UVOT Upper Limits
  27. GRB 191024A: Afterglow Upper Limits with LCO
  28. GRB 191024A: Swift-XRT refined Analysis
  29. GRB 191024A: GROND early upper limits
  30. GRB191024A: MASTER optical observation
  31. GRB 191024A: Enhanced Swift-XRT position
  32. GRB 191024A: Swift detection of a burst
  33. Swift GRB191020.89: Global MASTER-Net OT detection
  34. GRB 191019A: Swift/UVOT Detection
  35. HAWC-191019A: No Neutrino Counterpart detected with ANTARES
  36. GRB 191019A: Swift-XRT updated analysis
  37. Swift GRB191020.81: Global MASTER-Net OT detection
  38. GRB 191019A: Swift-BAT refined analysis
  39. GRB 191019A: Swift-XRT refined Analysis
  40. Swift GRB191019.67: Global MASTER-Net observations report
  41. GRB 191019A: Enhanced Swift-XRT position
  42. GRB 191019A: GROND observations
  43. GRB 191019A: Swift-XRT observations
  44. Swift GRB191019.63: Global MASTER-Net observations report
  45. GRB 191019A: MASTER optical observation
  46. GRB 191019A: Swift detection of a burst
  47. GRB 191017B: Swift-BAT refined analysis
  48. GRB 191017B: Swift/UVOT Upper Limits
  49. GRB 191017B: Swift-XRT refined Analysis
  50. GRB 191016A: Swift-XRT afterglow detection
  51. GRB 191016A: Swift/UVOT Detection
  52. GRB 191017B: Enhanced Swift-XRT position
  53. GRB 191017B: Swift detection of a burst
  54. GRB 191016A: early time BOOTES Network and follow-up 1.5m OSN optical observations
  55. GRB 191016A: Swift-BAT refined analysis
  56. GRB 191016A: KAIT Optical Afterglow Confirmation
  57. Swift GRB191016.17: Global MASTER-Net observations report
  58. GRB 191016A: Swift detection of a burst
  59. GRB 191011A: Swift-BAT refined analysis
  60. GRB 191011A: Swift/UVOT Detection
  61. GRB 191011A: RATIR Optical and NIR Observations
  62. GRB 191011A: Fermi GBM observation
  63. GRB 191011A: Swift-XRT refined Analysis
  64. GRB 191011A: Enhanced Swift-XRT position
  65. GRB 191011A: GROND Detection of the Optical/NIR afterglow
  66. GRB 191011A: VLT X-shooter redshift from RRM Observations
  67. Swift GRB191011.19: Global MASTER-Net observations report
  68. Swift GRB191011.19: Global MASTER-Net OT detection
  69. GRB 191011A: Swift detection of a burst with an optical counterpart
  70. LIGO/Virgo S190930t: Continued Swift observations of AT2019sbk
  71. GRB 191004A: CALET Gamma-Ray Burst Monitor detection
  72. GRB 191004B: Swift/UVOT Detection
  73. GRB 191004B: Continued Optical Afterglow Monitoring with LCO
  74. Konus-Wind observation of GRB 191004B
  75. Konus-Wind observation of GRB 191004A
  76. GRB 191004A: Swift/UVOT Detection
  77. GRB 191004A: Optical Detection with LCO
  78. LIGO/Virgo S190930t: Magellan/IMACS imaging of Swift J224718-581442 (AT2019sbk)
  79. LIGO/Virgo S190930t: Swift XRT observations, no secure afterglow found
  80. LIGO/Virgo S190930t: Swift discovery of Swift J224718-581442 (AT2019sbk): a fading UV transient with an X-ray counterpart
  81. LIGO/Virgo S190930t: Swift J221951-484240 optical photometry of Chilescope observatory
  82. LIGO/Virgo S190930t: SALT optical spectroscopy of Swift J221951-484240
  83. GRB 191004B: Swift-XRT refined Analysis
  84. GRB 191004B: GROND Detection of the Optical/NIR Afterglow
  85. GRB 191004A: GROND Upper limits
  86. GRB 191004B: COATLI Optical Observations
  87. GRB 191004A: Swift-XRT refined Analysis
  88. GRB 191004B: VLT/X-shooter redshift
  89. GRB 191004B: Swift-BAT refined analysis
  90. GRB 191004B: NOT optical photometry
  91. GRB 191004A: Swift-BAT refined analysis
  92. GRB 191004A: NOT optical upper limits
  93. GRB 191004B: Enhanced Swift-XRT position
  94. GRB 191004A: Enhanced Swift-XRT position
  95. GRB 191004B: Optical Afterglow Detection with LCO
  96. Swift GRB191004.9: Global MASTER-Net OT detection
  97. GRB 191004B: Swift detection of a burst with an optical counterpart
  98. GRB 191004A: Swift detection of a burst with an optical detection
  99. Swift GRB191004.75: Global MASTER-Net OT detection
  100. GRB 191001A: Swift-XRT observations

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