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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"

19599 results found.

  1. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  2. GRB 210807C: Swift-BAT refined analysis
  3. GRB 210807A: Detection by GRBAlpha
  4. GRB 210807A: Swift-BAT refined analysis
  5. GRB 210802A: Further Swift/XRT observation and afterglow confirmation
  6. GRB 210807C: Swift-XRT refined Analysis
  7. GRB 210807C: Fermi GBM detection
  8. GRB 210807C: Swift/UVOT Upper Limits
  9. GRB 210807A: Swift/UVOT Detection
  10. GRB 210807A: Swift-XRT refined Analysis
  11. GRB 210807C: Enhanced Swift-XRT position
  12. Swift GRB210807.74: Global MASTER-Net observations report
  13. Swift GRB210807.96: Global MASTER-Net observations report
  14. GRB 210807C: Swift detection of a burst
  15. Swift GRB 210807A: Global MASTER-Net observations report
  16. Swift GRB210807.79: Global MASTER-Net observations report
  17. Swift GRB210807.78: Global MASTER-Net observations report
  18. GRB 210807A: Enhanced Swift-XRT position
  19. GRB 210807A: BOOTES-5/JGT optical afterglow detection
  20. GRB 210807A: Swift detection of a burst with an optical counterpart
  21. IPN Triangulation of a bright burst from SGR 1935+2154
  22. GRB 210802A: BOOTES-2/TELMA optical upper limit
  23. GRB 210802A: Swift-XRT afterglow detection
  24. GRB 210802A: Fermi-LAT detection
  25. GRB 210802A: Tiled Swift observations
  26. GRB 210731A: continued GROND observations
  27. GRB 210731A: KAIT Optical Detection
  28. GRB 210731A: Swift-BAT refined analysis
  29. GRB 210731A: MASTER optical afterglow detection
  30. GRB 210731A: Swift-XRT refined Analysis
  31. GRB 210731A: GROND observations
  32. GRB 210731A: Fermi GBM Observation
  33. GRB 210731A: Swift/UVOT Detection of an optical afterglow
  34. Swift GRB210731.62: Global MASTER-Net observations report
  35. GRB 210731A: MeerLICHT optical afterglow detection
  36. GRB210731A: Enhanced Swift-XRT position
  37. GRB 210731A: Swift detection of a burst
  38. Swift GRB210731.93: Global MASTER-Net observations report
  39. Trigger 1062273: Swift detection of 4U 1700-377
  40. GRB 210730A: BOOTES-5/JGT and 2.2m CAHA telescopes optical limit
  41. Swift GRB 210730A: Global MASTER-Net observations report
  42. GRB 210726A: Chandra detection of the X-ray afterglow
  43. GRB 210730A: Fermi GBM observation
  44. GRB 210730A: AstroSat CZTI detection
  45. GRB 210730A: Swift-BAT refined analysis
  46. GRB 210730A: Swift-XRT refined Analysis
  47. GRB 210730A: Swift/UVOT Upper Limits
  48. GRB 210730A: Enhanced Swift-XRT position
  49. GRB 210730A: Swift detection of a burst near M82
  50. GRB 210724A: Corrected Swift-XRT enhanced position
  51. Fermi GBM Sub-Threshold Detection of GRB 210725B
  52. IPN triangulation of GRB 210727A (short)
  53. Fermi GBM Sub-Threshold Detection of GRB 210726A
  54. GRB 210726A: Swift-XRT refined Analysis
  55. GRB 210726A: Swift-BAT refined analysis
  56. GRB 210726A: Likely a short burst
  57. GRB 210726A: RATIR Optical Upper Limits and Candidate Host Galaxy
  58. GRB 210724A: Swift/UVOT Upper Limits
  59. GRB 210723A: Swift/UVOT Upper Limits
  60. GRB 210725A: Swift/UVOT Upper Limits
  61. GRB 210725B: Swift/UVOT Upper Limits
  62. GRB 210726A: CAHA 2.2m telescope optical limit
  63. GRB 210726A: Enhanced Swift-XRT position
  64. GRB 210726A: Swift detection of a burst
  65. Swift GRB210726.80: Global MASTER-Net observations report
  66. GRB 210725B: Swift-XRT refined Analysis
  67. GRB 210725A: Fermi GBM detection
  68. GRB 210725A: Swift-XRT refined Analysis
  69. GRB 210725B: Swift-BAT refined analysis
  70. GRB 210724A: Swift-XRT refined Analysis
  71. GRB 210725A: Swift-BAT refined analysis
  72. GRB 210724A: Swift-BAT refined analysis
  73. Swift GRB 210725B: Global MASTER-Net observations report
  74. GRB 210725B: Enhanced Swift-XRT position
  75. GRB 210725A: MITSuME Akeno optical upper limits
  76. GRB 210725B: Swift detection of a burst
  77. GRB 210725A: CALET Gamma-Ray Burst Monitor detection
  78. GRB 210723A: CALET Gamma-Ray Burst Monitor detection
  79. GRB 210725A: KAIT Optical Upper Limit
  80. GRB 210725A: Swift detection of a burst
  81. Swift GRB210725.16: Global MASTER-Net observations report
  82. GRB 210723A: Fermi GBM Observation
  83. GRB210724A: MeerLICHT upper limits
  84. GRB 210724A: Swift detection of a burst
  85. Swift GRB210724.84: Global MASTER-Net observations report
  86. GRB 210723A: Swift-BAT refined analysis
  87. GRB 210723A: Swift-XRT refined Analysis
  88. Swift GRB 210723A: Global MASTER-Net observations report
  89. GRB 210722A: Fermi GBM observation
  90. GRB 210722A: Swift-BAT refined analysis
  91. GRB 210723A: Prompt enhanced Swift-XRT position
  92. GRB 210723A: Swift detection of a burst
  93. GRB 210722A: Swift-XRT refined Analysis
  94. GRB 210722A: Swift/UVOT Detection
  95. GRB 210722A: GIT optical detection and preliminary analysis
  96. Swift GRB 210722A: Global MASTER-Net observations report
  97. GRB 210722A: Nanshan/NEXT optical afterglow observations
  98. GRB 210722A: Swift detection of a burst with a bright optical counterpart
  99. GRB 210712A: Swift-BAT refined analysis
  100. GRB 210712A: Swift-XRT refined Analysis

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