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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').

17104 results found.

  1. GRB 240514E: A possible candidate BD-21 1074
  2. GRB 240516A: Fermi GBM Observation
  3. GRB 240516A: GOTO optical upper limit
  4. GRB 240516A: Swift detection of a burst
  5. Swift GRB240516.15: Global MASTER-Net observations report
  6. GRB 240513A: Swift-XRT observations
  7. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  8. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  9. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  10. GRB 240513A: Tiled Swift observations
  11. GRB 240513A: Fermi-LAT detection
  12. GRB 240511A: Fermi GBM Observation
  13. GRB 240511A: Swift-BAT refined analysis
  14. GRB 240511A: J-band observations with WINTER
  15. GRB 240511A: Enhanced Swift-XRT position
  16. GRB 240511A : MITSuME Akeno optical upper limits
  17. GRB 240511A: Swift-XRT refined Analysis
  18. Swift GRB 240511A: Global MASTER-Net observations report
  19. GRB 240511A: Prompt enhanced Swift-XRT position
  20. GRB 240511A: Swift detection of a burst
  21. GRB 240504A: Fermi GBM Observation
  22. IPN triangulation of GRB 240504A
  23. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  24. GRB 240415A 1.3m DFOT Optical upper limit
  25. LIGO/Virgo S240422ed: Swift XRT observation of EP240426a
  26. LVK S240422ed: Further Swift-XRT followup of three sources
  27. LIGO/Virgo/KAGRA S240422ed: Magellan Follow-up Observations of Swift/XRT candidates
  28. LIGO/Virgo/KAGRA S240422ed: 2.5m PRL Telescope follow-up of the Swift/XRT source S240422ed_X190
  29. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  30. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limits for Swift/XRT candidates
  31. GRB 240419B: Swift-BAT refined analysis
  32. GRB 240421B: Swift-BAT refined analysis
  33. LIGO/Virgo/KAGRA S240422ed: Himalayan Chandra Telescope follow-up of the Swift/XRT source S240422ed_X101
  34. IceCube-240424A - IceCube observation of a high-energy neutrino candidate track-like event
  35. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  36. LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
  37. LIGO/Virgo/KAGRA S240422ed: NOT J-band upper limit on the Swift/XRT source S240422ed_X61
  38. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Three Potential Electromagnetic Counterparts Reported So Far
  39. GRB 240421B: GRBAlpha detection
  40. LIGO/Virgo/KAGRA S240422ed: WINTER J-band upper limits on the Swift/XRT source S240422ed_X61
  41. LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam upper limits on the Swift/XRT source S240422ed_X61
  42. GRB 240419A: Swift-BAT refined analysis
  43. GRB 240418A: Swift-BAT refined analysis
  44. LXT240402A/GRB240402B: Chandra X-ray detection
  45. LIGO/Virgo/KAGRA S240421ar: Upper limits from Swift/BAT-GUANO
  46. GRB 240419B : MITSuME Akeno optical upper limits
  47. GRB 240415B: Swift-XRT observations
  48. GRB 240415A: Swift-XRT refined Analysis
  49. GRB 240421B: AstroSat CZTI detection
  50. GRB240421B: Zadko Observations
  51. Swift GRB 240421B: Global MASTER-Net observations report
  52. GRB 240421B: Fermi GBM Observation
  53. GRB 240421B: Swift-XRT refined Analysis
  54. GRB240421B: BOOTES-5/JGT optical upper limit
  55. GRB 240421B: Swift/UVOT Upper Limits
  56. GRB 240421B: Enhanced Swift-XRT position
  57. GRB 240421B: Swift detection of a burst
  58. GRB240419A: Skynet Optical Afterglow Analysis
  59. GRB 240419B: Swift/UVOT Upper Limits
  60. GRB 240419A: Swift/UVOT Upper Limits
  61. GRB 240419B: Swift-XRT refined Analysis
  62. Swift GRB 240419B: Global MASTER-Net observations report
  63. GRB 240419B: Enhanced Swift-XRT position
  64. Swift GRB 240419A: Global MASTER-Net observations report
  65. GRB 240418A: Swift/UVOT Upper Limits
  66. GRB 240419A: Swift-XRT refined Analysis
  67. GRB 240418A: Swift-XRT refined Analysis
  68. GRB 240419B: Swift detection of a burst
  69. GRB 240411B: Swift/UVOT Detection
  70. GRB240418A: YAHPT Upper Limits
  71. GRB 240419A: Enhanced Swift-XRT position
  72. GRB 240419A: Prompt enhanced Swift-XRT position
  73. GRB 240419A: Swift detection of a burst
  74. GRB 240418A: TSHAO Zeiss-1000 optical upper limit
  75. GRB 240418A: Enhanced Swift-XRT position
  76. Swift GRB240418.85: Global MASTER-Net observations report
  77. GRB 240418A: Swift detection of a burst
  78. Improved IPN triangulation of GRB 240411A
  79. GRB 240415A: Glowbug gamma-ray detection
  80. GRB 240414A: Glowbug gamma-ray detection
  81. GRB 240415B: GECAM-B detection
  82. GRB 240415A: Swift-BAT refined analysis
  83. GRB 240411A: Glowbug gamma-ray detection
  84. GRB 240414A: Swift-BAT refined analysis
  85. GRB 240414A: AbAO optical upprer limit
  86. GRB 240415A: Swift/UVOT Detection
  87. GRB 240415A: Fermi GBM Observation
  88. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  89. GRB 240415A: Enhanced Swift-XRT position
  90. GRB 240415B: Swift ToO observations
  91. GRB 240415B: Swift/BAT-GUANO Correction
  92. GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
  93. GRB 240414A: Fermi GBM Observation
  94. GRB 240414A: Swift/UVOT Detection
  95. LXT 240402A/GRB 240402B: Swift follow-up observations
  96. GRB 240414A: Mondy optical observations
  97. GRB 240415A: Prompt Swift-XRT observations
  98. GRB 240415A: Swift detection of a burst
  99. GRB 240414A: Swift-XRT refined Analysis
  100. GRB 240414A: Enhanced Swift-XRT position

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