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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').

18304 results found.

  1. GRB 240811A: LCOGT Optical Upper Limit
  2. GRB 240811A: Enhanced Swift-XRT position
  3. Konus-Wind detection of GRB 240809A
  4. Swift GRB 240811A: Global MASTER-Net observations report
  5. GRB 240811A: Swift detection of a burst
  6. GRB 240809A: Bassano Bresciano Observatory optical observations
  7. GRB 240809A: KAIT optical observations
  8. GRB 240809A: GIT afterglow observations
  9. GRB 240809A: Swift/UVOT Detection
  10. GRB 240809A: Swift-XRT refined Analysis
  11. IPN triangulation of GRB 240807A / EP 240807a
  12. Swift GRB 240809A: Global MASTER-Net observations report
  13. GRB 240809A: JinShan optical observations
  14. GRB 240809A: Enhanced Swift-XRT position
  15. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  16. GRB 240809A: SVOM/GRM observation
  17. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  18. GRB 240805A: ATCA Radio Upper Limits
  19. GRB 240805B: GIT optical upper limit
  20. GRB 240805B: Swift-BAT refined analysis
  21. GRB 240805A: Swift-BAT refined analysis
  22. Konus-Wind detection of GRB 240805A
  23. GRB 240805B Bassano Bresciano Observatory upper limit
  24. GRB240805A: Fermi GBM Observation
  25. GRB 240805B: JinShan optical afterglow detection
  26. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  27. GRB 240805B: Swift-XRT refined Analysis
  28. GRB 240805B: Swift/UVOT Upper Limits
  29. GRB 240805A: Swift/UVOT Upper Limits
  30. GRB 240805A: SVOM/GRM observation
  31. GRB 240805B: Enhanced Swift-XRT position
  32. GRB 240805B: LCOGT Optical Upper Limits
  33. Swift GRB 240805B: Global MASTER-Net observations report
  34. GRB 240805B: JinShan optical upper limits
  35. Swift GRB 240805A: Global MASTER-Net observations report
  36. GRB 240805A: Swift-XRT refined Analysis
  37. GRB 240805B: Swift detection of a burst
  38. GRB 240805A: Fermi-LAT detection
  39. GRB 240805A: INTEGRAL spectral analysis
  40. GRB 240805A: A long GRB detected by INTEGRAL
  41. GRB 240805A: Swift detection of a burst
  42. GRB 240730A: Swift-BAT refined analysis
  43. GRB240730A: BOOTES-5/JGT early optical upper limit
  44. Swift GRB 240730A: Global MASTER-Net observations report
  45. GRB 240730A: Swift-XRT refined Analysis
  46. GRB 240715A: Swift-XRT afterglow detection
  47. GRB 240730A: KAIT Optical Upper Limit
  48. GRB 240730A: Swift/UVOT Upper Limits
  49. GRB 240730A: Enhanced Swift-XRT position
  50. GRB 240730A: Swift detection of a burst
  51. GRB 240727A: Swift-BAT refined analysis
  52. LIGO/Virgo/KAGRA S240615dg: GRAWITA wide-field optical observations
  53. GRB 240727A: observations of optical counterpart.
  54. GRB 240727B: Swift-XRT observations
  55. GRB 240727A: Swift/UVOT detection
  56. GRB 240727A: NOT optical observation
  57. GRB 240727A: JinShan optical upper limits
  58. GRB 240727A Bassano Bresciano Observatory upper limit
  59. GRB 240727A: Swift-XRT refined Analysis
  60. GRB 240727A: Enhanced Swift-XRT position
  61. GRB 240727B: Fermi GBM Observation
  62. Swift GRB240727.16: Global MASTER-Net observations report
  63. GRB 240727B: Swift ToO observations
  64. GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
  65. GRB240727A: Skynet Optical Afterglow Observations
  66. GRB 240727A: TRT optical afterglow detection
  67. GRB 240727A: KAIT Optical Afterglow Candidate
  68. GRB 240727A: Swift detection of a burst
  69. Swift Trigger 1244778 is not a GRB
  70. Swift GRB240725.11: Global MASTER-Net observations report
  71. GRB 240720A: Swift-BAT refined analysis
  72. LIGO/Virgo/KAGRA S240716b: Upper limits from Swift/BAT-GUANO
  73. LIGO/Virgo/KAGRA S240703ad: Upper limits from Swift/BAT-GUANO
  74. GRB 240720A: AstroSat CZTI detection
  75. GRB 240720A: Fermi GBM observation
  76. GRB 240720A: Swift detection of a burst
  77. Swift GRB240720.02: Global MASTER-Net observations report
  78. GRB 240718A: Fermi-LAT Detection
  79. GRB 240712A: Swift-BAT refined analysis
  80. GRB 240715A: Swift/UVOT observations of the XRT sources.
  81. GRB 240715A: Swift-XRT observations
  82. GRB240713A: Swift/UVOT Upper LImits
  83. EP240708a: X-ray follow-up observations with Swift/XRT
  84. GRB 240713A: Swift-XRT observations
  85. GRB 240715A: TRT optical upper limit on one Swift/XRT candidate
  86. GRB 240712A: Swift-XRT refined Analysis
  87. GRB 240715A: Swift ToO observations
  88. GRB 240712A ATCA radio observations
  89. IPN triangulation of GRB 240715A (short)
  90. GW s240422ed: Swift UVOT follow-up
  91. GRB 240712A: Swift/UVOT Upper Limits
  92. The EP-WXT source triggered on July 14th is likely a flaring star
  93. GRB 240713A: Tiled Swift observations
  94. GRB 240712A: Swift detection of a burst
  95. EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
  96. EP240708a: EP-WXT detection of a fast X-ray transient
  97. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  98. IPN triangulation of GRB 240628B (short)
  99. EP240703a and EP240703b: Swift/XRT upper limits
  100. EP240703c: Kinder optical follow-up and Swift XRT observations

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