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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"

19603 results found.

  1. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  2. IPN triangulation of GRB 240619C
  3. GRB 240624A: Swift-BAT refined analysis
  4. Konus-Wind detection of GRB 240619A
  5. GRB240624A: Fermi GBM Observation
  6. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  7. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  8. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  9. Swift GRB 240624A: Global MASTER-Net observations report
  10. GRB 240624A: Swift detection of a burst
  11. GRB 240529A: JinShan optical observations
  12. IPN triangulation of GRB 240615A (short)
  13. EP240618a: Swift/XRT upper limit
  14. EP240617a: tentative Swift/XRT detection of the afterglow
  15. GRB 240619A: Swift-XRT probable afterglow detection
  16. GRB 240619A: Swift ToO observations
  17. GRB 240615A: NOT optical observations
  18. GRB 240615A: possible transient detection from Wendelstein observations
  19. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  20. GRB240615A: 1.3m DFOT optical upper limit
  21. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  22. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  23. GRB 240615A: J-band upper limits from WINTER
  24. GRB 240615A: Fermi GBM Observation
  25. GRB 240615A: Swift-XRT observations
  26. GRB 240615A: GECAM detection
  27. GRB 240615A: FLWO-1.2m optical upper limits
  28. Konus-Wind detection of GRB 240615A (short/hard)
  29. GRB 240615A: GOTO optical upper limits
  30. GRB 240615A: Swift ToO observations
  31. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  32. EXO 0748-676: Swift-BAT refined analysis
  33. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  34. GRB 240529A: LBT optical detection and late temporal decay
  35. GRB 240529A : MITSuME Akeno optical afterglow detection
  36. Trigger 1236151: Swift detection of EXO 0748-676
  37. IPN triangulation of GRB 240607A
  38. Konus-Wind detection of GRB 240606B
  39. GRB 240606B: Fermi GBM Observation
  40. Swift Trigger 1235109: consistent with noise and not astrophysical
  41. GRB 240606B: GECAM-B detection a long burst
  42. GRB 240606B: Swift-XRT afterglow detection
  43. Swift GRB240606.15: Global MASTER-Net observations report
  44. GRB 240606B: Swift ToO observations
  45. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  46. Swift Trigger 1235109: a possible GRB 240606A
  47. IPN triangulation of GRB 240531A (short)
  48. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  49. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  50. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  51. Swift Trigger 1232465: consistent with noise
  52. GRB 240603B: Swift detection of a possible burst
  53. GRB 240529A: MASTER prompt OT detection
  54. GRB 240529A: OSN optical detection
  55. Swift Trigger 1232465 is not a GRB
  56. GRB 240529A: 1.3m DFOT Optical observations
  57. Konus-Wind detection of GRB 240529A
  58. IPN triangulation of the initial episode of GRB 240529A
  59. GRB 240529A: MAAO 0.7m telescope optical afterglow detection
  60. GRB 240529A: Insight-HXMT/HE detection
  61. GRB 240529A: GROWTH-India optical follow-up
  62. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  63. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  64. GRB 240529A: Skynet Optical Observations
  65. GRB 240529A: Swift-BAT refined analysis
  66. GRB 240529A: Swift-XRT refined Analysis
  67. GRB240529A: BOOTES-6/DPRT optical detection
  68. GRB 240529A: Swift/UVOT Detection
  69. GRB 240529A: NOT optical observations
  70. GRB 240529A: AstroSat CZTI detection
  71. GRB 240529A: GOTO optical afterglow detection
  72. GRB 240527B: Swift-XRT afterglow detection
  73. GRB 240529A: Enhanced Swift-XRT position
  74. GRB 240529A: Swift detection of a burst with an optical counterpart
  75. Swift GRB240529.12: Global MASTER-Net observations report
  76. GRB 240527B: Fermi-LAT detection
  77. GRB 240523A: Swift-BAT refined analysis
  78. GRB 240523A: Swift-XRT refined Analysis
  79. GRB 240523A: Enhanced Swift-XRT position
  80. GRB 240523A: Swift detection of a burst
  81. GRB 240521B: Fermi GBM Observation
  82. GRB 240513A: Swift-XRT afterglow detection
  83. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
  84. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  85. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  86. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  87. GRB 240504A: VZLUSAT-2 detection
  88. GRB 240516A: Swift/UVOT Upper Limits
  89. GRB 240516A: Swift-BAT refined analysis
  90. GRB 240516A ATCA radio observations
  91. IPN triangulation of GRB 240514B (short)
  92. GRB 240513A: Swift ToO observations
  93. GRB 240516A: AstroSat CZTI detection
  94. GRB 240516A: Swift-XRT refined Analysis
  95. GRB 240514E: A possible candidate BD-21 1074
  96. GRB 240516A: Fermi GBM Observation
  97. GRB 240516A: GOTO optical upper limit
  98. GRB 240516A: Swift detection of a burst
  99. Swift GRB240516.15: Global MASTER-Net observations report
  100. GRB 240513A: Swift-XRT observations

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