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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"

32140 results found.

  1. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  2. GRB 240615A: J-band upper limits from WINTER
  3. GRB 240615A: Fermi GBM Observation
  4. GRB 240615A: Swift-XRT observations
  5. GRB 240615A: GECAM detection
  6. GRB 240615A: FLWO-1.2m optical upper limits
  7. Fermi GRB 240616A: Global MASTER-Net observations report
  8. Konus-Wind detection of GRB 240615A (short/hard)
  9. GRB 240615A: GOTO optical upper limits
  10. GRB 240616A: Fermi GBM Final Real-time Localization
  11. GRB 240615A: Swift ToO observations
  12. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  13. GRB 240615A: Fermi GBM Final Real-time Localization
  14. GRB 240603A: VZLUSAT-2 detection
  15. GRB 240612A: GRBAlpha detection
  16. GRB 240613A: Fermi GBM Final Real-time Localization
  17. Fermi GRB 240612B: Global MASTER-Net observations report
  18. Fermi GRB 240612A: Global MASTER-Net observations report
  19. GRB 240612B: Fermi GBM Final Real-time Localization
  20. GRB 240612A: Fermi GBM Final Real-time Localization
  21. GRB 240607A: GECAM detection of a bright long burst
  22. Fermi GRB 240611A: Global MASTER-Net observations report
  23. Konus-Wind detection of GRB 240607A
  24. GRB 240611A: Fermi GBM Final Real-time Localization
  25. GRB 240529A: LBT optical detection and late temporal decay
  26. GRB 240529A : MITSuME Akeno optical afterglow detection
  27. Fermi GRB 240610A: Global MASTER-Net observations report
  28. GRB 240610A: Fermi GBM Final Real-time Localization
  29. IPN triangulation of GRB 240607A
  30. Fermi Gamma-ray Burst Monitor trigger 739632045/240609556 is not a GRB
  31. Fermi GRB 240608A: Global MASTER-Net observations report
  32. Konus-Wind detection of GRB 240606B
  33. GRB 240608A: Fermi GBM Final Real-time Localization
  34. Fermi GRB 240607A: Global MASTER-Net observations report
  35. GRB 240529A: NOEMA detection
  36. GRB 240607A: Fermi GBM Observation
  37. GRB 240606B: Fermi GBM Observation
  38. Swift Trigger 1235109: consistent with noise and not astrophysical
  39. GRB 240607A: AstroSat CZTI detection of bright long burst
  40. GRB 240607A: Fermi GBM detection of a very bright burst
  41. GRB 240529A: radio detection with AMI-LA
  42. GRB 240607A: BALROG localization (Fermi Trigger 739450879 / GRB 240607459)
  43. GRB 240607A: Fermi GBM Final Real-time Localization
  44. GRB 240606B: GECAM-B detection a long burst
  45. GRB 240606B: Swift-XRT afterglow detection
  46. GRB 240606B: Swift ToO observations
  47. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  48. Konus-Wind detection of GRB 240603A
  49. Swift Trigger 1235109: a possible GRB 240606A
  50. Fermi GRB 240604A: Global MASTER-Net observations report
  51. IPN triangulation of GRB 240531A (short)
  52. Fermi GRB 240605A: Global MASTER-Net observations report
  53. Fermi GRB 240605C: Global MASTER-Net observations report
  54. Fermi Gamma-ray Burst Monitor trigger 739290883/240605607 is not a GRB
  55. GRB 240605C: Fermi GBM Final Real-time Localization
  56. IPN triangulation of GRB 240603A
  57. GRB 240605B: Fermi GBM Final Real-time Localization
  58. GRB 240604A: Fermi GBM Final Localization
  59. GRB 240605A: Fermi GBM Final Real-time Localization
  60. GRB 240604A: GECAM detection of a long burst
  61. GRB 240529A: SAO RAS optical observations
  62. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  63. Fermi GRB 240603C: Global MASTER-Net observations report
  64. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  65. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  66. GRB 240603A: Fermi GBM Final Localization
  67. GRB 240603C: BALROG localization (Fermi Trigger 739102156 / GRB 240603423)
  68. GRB 240603C: Fermi GBM Final Real-time Localization
  69. GRB 240603B: Swift detection of a possible burst
  70. GRB 240529A: MASTER prompt OT detection
  71. GRB 240603A: GECAM detection of a short burst
  72. GRB 240529A: continued SAO RAS optical observations
  73. Fermi GRB 240602A: Global MASTER-Net observations report
  74. GRB 240529A: OSN optical detection
  75. GRB 240529A: further SAO RAS optical observations
  76. GRB 240602A: Fermi GBM Final Real-time Localization
  77. Swift Trigger 1232465 is not a GRB
  78. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  79. GRB 240529A: 1.3m DFOT Optical observations
  80. GRB 240531A: AstroSat CZTI detection of a short burst
  81. GRB 240529A : Mondy optical observations
  82. Konus-Wind detection of GRB 240529A
  83. IPN triangulation of the initial episode of GRB 240529A
  84. GRB 240529A: SAO RAS optical observations
  85. GRB 240529A: MAAO 0.7m telescope optical afterglow detection
  86. GRB 240529A: Insight-HXMT/HE detection
  87. GRB 240529A: optical photometry from Konkoly
  88. GRB 240529A: GROWTH-India optical follow-up
  89. GRB 240529A: T193/MISTRAL observations
  90. GRB 240529A: Redshift from GTC/OSIRIS+
  91. GRB 240529A: AKO Optical Afterglow Detection
  92. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  93. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  94. GRB 240529A: J-band detections with WINTER
  95. GRB 240529A: Skynet Optical Observations
  96. GRB 240529A: Swift-BAT refined analysis
  97. GRB 240529A: Swift-XRT refined Analysis
  98. GRB240529A: BOOTES-6/DPRT optical detection
  99. GRB 240529A: Swift/UVOT Detection
  100. GRB 240529A: NOT optical observations

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