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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"

19587 results found.

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

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