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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"

19594 results found.

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

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