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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').

17103 results found.

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

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