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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"

19935 results found.

  1. EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
  2. EP240708a: EP-WXT detection of a fast X-ray transient
  3. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  4. IPN triangulation of GRB 240628B (short)
  5. EP240703a and EP240703b: Swift/XRT upper limits
  6. EP240703c: Kinder optical follow-up and Swift XRT observations
  7. EP240703c: EP-WXT detection of an X-ray transient
  8. IPN triangulation of GRB 240627A
  9. EP240703b: EP-WXT detection of a fast X-ray transient
  10. EP240702a: Swift/XRT upper limit
  11. EP240703a: EP-WXT detection of a fast X-ray transient
  12. EP240702a: EP-WXT detection of a fast X-ray transient
  13. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  14. IPN triangulation of GRB 240619C
  15. GRB 240624A: Swift-BAT refined analysis
  16. Konus-Wind detection of GRB 240619A
  17. GRB240624A: Fermi GBM Observation
  18. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  19. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  20. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  21. Swift GRB 240624A: Global MASTER-Net observations report
  22. GRB 240624A: Swift detection of a burst
  23. GRB 240529A: JinShan optical observations
  24. IPN triangulation of GRB 240615A (short)
  25. EP240618a: Swift/XRT upper limit
  26. EP240617a: tentative Swift/XRT detection of the afterglow
  27. GRB 240619A: Swift-XRT probable afterglow detection
  28. GRB 240619A: Swift ToO observations
  29. GRB 240615A: NOT optical observations
  30. GRB 240615A: possible transient detection from Wendelstein observations
  31. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  32. GRB240615A: 1.3m DFOT optical upper limit
  33. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  34. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  35. GRB 240615A: J-band upper limits from WINTER
  36. GRB 240615A: Fermi GBM Observation
  37. GRB 240615A: Swift-XRT observations
  38. GRB 240615A: GECAM detection
  39. GRB 240615A: FLWO-1.2m optical upper limits
  40. Konus-Wind detection of GRB 240615A (short/hard)
  41. GRB 240615A: GOTO optical upper limits
  42. GRB 240615A: Swift ToO observations
  43. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  44. EXO 0748-676: Swift-BAT refined analysis
  45. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  46. GRB 240529A: LBT optical detection and late temporal decay
  47. GRB 240529A : MITSuME Akeno optical afterglow detection
  48. Trigger 1236151: Swift detection of EXO 0748-676
  49. IPN triangulation of GRB 240607A
  50. Konus-Wind detection of GRB 240606B
  51. GRB 240606B: Fermi GBM Observation
  52. Swift Trigger 1235109: consistent with noise and not astrophysical
  53. GRB 240606B: GECAM-B detection a long burst
  54. GRB 240606B: Swift-XRT afterglow detection
  55. Swift GRB240606.15: Global MASTER-Net observations report
  56. GRB 240606B: Swift ToO observations
  57. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  58. Swift Trigger 1235109: a possible GRB 240606A
  59. IPN triangulation of GRB 240531A (short)
  60. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  61. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  62. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  63. Swift Trigger 1232465: consistent with noise
  64. GRB 240603B: Swift detection of a possible burst
  65. GRB 240529A: MASTER prompt OT detection
  66. GRB 240529A: OSN optical detection
  67. Swift Trigger 1232465 is not a GRB
  68. GRB 240529A: 1.3m DFOT Optical observations
  69. Konus-Wind detection of GRB 240529A
  70. IPN triangulation of the initial episode of GRB 240529A
  71. GRB 240529A: MAAO 0.7m telescope optical afterglow detection
  72. GRB 240529A: Insight-HXMT/HE detection
  73. GRB 240529A: GROWTH-India optical follow-up
  74. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  75. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  76. GRB 240529A: Skynet Optical Observations
  77. GRB 240529A: Swift-BAT refined analysis
  78. GRB 240529A: Swift-XRT refined Analysis
  79. GRB240529A: BOOTES-6/DPRT optical detection
  80. GRB 240529A: Swift/UVOT Detection
  81. GRB 240529A: NOT optical observations
  82. GRB 240529A: AstroSat CZTI detection
  83. GRB 240529A: GOTO optical afterglow detection
  84. GRB 240527B: Swift-XRT afterglow detection
  85. GRB 240529A: Enhanced Swift-XRT position
  86. GRB 240529A: Swift detection of a burst with an optical counterpart
  87. Swift GRB240529.12: Global MASTER-Net observations report
  88. GRB 240527B: Fermi-LAT detection
  89. GRB 240523A: Swift-BAT refined analysis
  90. GRB 240523A: Swift-XRT refined Analysis
  91. GRB 240523A: Enhanced Swift-XRT position
  92. GRB 240523A: Swift detection of a burst
  93. GRB 240521B: Fermi GBM Observation
  94. GRB 240513A: Swift-XRT afterglow detection
  95. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
  96. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  97. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  98. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  99. GRB 240504A: VZLUSAT-2 detection
  100. GRB 240516A: Swift/UVOT Upper Limits

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