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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').
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"

19596 results found.

  1. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  2. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  3. Swift GRB 240624A: Global MASTER-Net observations report
  4. GRB 240624A: Swift detection of a burst
  5. GRB 240529A: JinShan optical observations
  6. IPN triangulation of GRB 240615A (short)
  7. EP240618a: Swift/XRT upper limit
  8. EP240617a: tentative Swift/XRT detection of the afterglow
  9. GRB 240619A: Swift-XRT probable afterglow detection
  10. GRB 240619A: Swift ToO observations
  11. GRB 240615A: NOT optical observations
  12. GRB 240615A: possible transient detection from Wendelstein observations
  13. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  14. GRB240615A: 1.3m DFOT optical upper limit
  15. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  16. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  17. GRB 240615A: J-band upper limits from WINTER
  18. GRB 240615A: Fermi GBM Observation
  19. GRB 240615A: Swift-XRT observations
  20. GRB 240615A: GECAM detection
  21. GRB 240615A: FLWO-1.2m optical upper limits
  22. Konus-Wind detection of GRB 240615A (short/hard)
  23. GRB 240615A: GOTO optical upper limits
  24. GRB 240615A: Swift ToO observations
  25. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  26. EXO 0748-676: Swift-BAT refined analysis
  27. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  28. GRB 240529A: LBT optical detection and late temporal decay
  29. GRB 240529A : MITSuME Akeno optical afterglow detection
  30. Trigger 1236151: Swift detection of EXO 0748-676
  31. IPN triangulation of GRB 240607A
  32. Konus-Wind detection of GRB 240606B
  33. GRB 240606B: Fermi GBM Observation
  34. Swift Trigger 1235109: consistent with noise and not astrophysical
  35. GRB 240606B: GECAM-B detection a long burst
  36. GRB 240606B: Swift-XRT afterglow detection
  37. Swift GRB240606.15: Global MASTER-Net observations report
  38. GRB 240606B: Swift ToO observations
  39. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  40. Swift Trigger 1235109: a possible GRB 240606A
  41. IPN triangulation of GRB 240531A (short)
  42. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  43. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  44. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  45. Swift Trigger 1232465: consistent with noise
  46. GRB 240603B: Swift detection of a possible burst
  47. GRB 240529A: MASTER prompt OT detection
  48. GRB 240529A: OSN optical detection
  49. Swift Trigger 1232465 is not a GRB
  50. GRB 240529A: 1.3m DFOT Optical observations
  51. Konus-Wind detection of GRB 240529A
  52. IPN triangulation of the initial episode of GRB 240529A
  53. GRB 240529A: MAAO 0.7m telescope optical afterglow detection
  54. GRB 240529A: Insight-HXMT/HE detection
  55. GRB 240529A: GROWTH-India optical follow-up
  56. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  57. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  58. GRB 240529A: Skynet Optical Observations
  59. GRB 240529A: Swift-BAT refined analysis
  60. GRB 240529A: Swift-XRT refined Analysis
  61. GRB240529A: BOOTES-6/DPRT optical detection
  62. GRB 240529A: Swift/UVOT Detection
  63. GRB 240529A: NOT optical observations
  64. GRB 240529A: AstroSat CZTI detection
  65. GRB 240529A: GOTO optical afterglow detection
  66. GRB 240527B: Swift-XRT afterglow detection
  67. GRB 240529A: Enhanced Swift-XRT position
  68. GRB 240529A: Swift detection of a burst with an optical counterpart
  69. Swift GRB240529.12: Global MASTER-Net observations report
  70. GRB 240527B: Fermi-LAT detection
  71. GRB 240523A: Swift-BAT refined analysis
  72. GRB 240523A: Swift-XRT refined Analysis
  73. GRB 240523A: Enhanced Swift-XRT position
  74. GRB 240523A: Swift detection of a burst
  75. GRB 240521B: Fermi GBM Observation
  76. GRB 240513A: Swift-XRT afterglow detection
  77. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
  78. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  79. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  80. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  81. GRB 240504A: VZLUSAT-2 detection
  82. GRB 240516A: Swift/UVOT Upper Limits
  83. GRB 240516A: Swift-BAT refined analysis
  84. GRB 240516A ATCA radio observations
  85. IPN triangulation of GRB 240514B (short)
  86. GRB 240513A: Swift ToO observations
  87. GRB 240516A: AstroSat CZTI detection
  88. GRB 240516A: Swift-XRT refined Analysis
  89. GRB 240514E: A possible candidate BD-21 1074
  90. GRB 240516A: Fermi GBM Observation
  91. GRB 240516A: GOTO optical upper limit
  92. GRB 240516A: Swift detection of a burst
  93. Swift GRB240516.15: Global MASTER-Net observations report
  94. GRB 240513A: Swift-XRT observations
  95. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  96. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  97. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  98. GRB 240513A: Tiled Swift observations
  99. GRB 240513A: Fermi-LAT detection
  100. GRB 240511A: Fermi GBM Observation

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