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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').
  1. GRB 240616A: Fermi GBM Final Real-time Localization
  2. GRB 240615A: Swift ToO observations
  3. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  4. GRB 240615A: Fermi GBM Final Real-time Localization
  5. LIGO/Virgo/KAGRA S240615ea: Identification of a GW compact binary merger candidate
  6. LIGO/Virgo/KAGRA S240615dg: Identification of a GW compact binary merger candidate
  7. GRB 240603A: VZLUSAT-2 detection
  8. GRB 240612A: GRBAlpha detection
  9. GRB 240613A: Fermi GBM Final Real-time Localization
  10. Fermi GRB 240612B: Global MASTER-Net observations report
  11. Fermi GRB 240612A: Global MASTER-Net observations report
  12. GRB 240612B: Fermi GBM Final Real-time Localization
  13. GRB 240612A: Fermi GBM Final Real-time Localization
  14. GRB 240607A: GECAM detection of a bright long burst
  15. Fermi GRB 240611A: Global MASTER-Net observations report
  16. Konus-Wind detection of GRB 240607A
  17. GRB 240611A: Fermi GBM Final Real-time Localization
  18. EXO 0748-676: Swift-BAT refined analysis
  19. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  20. GRB 240529A: LBT optical detection and late temporal decay
  21. GRB 240529A : MITSuME Akeno optical afterglow detection
  22. Trigger 1236151: Swift detection of EXO 0748-676
  23. Fermi GRB 240610A: Global MASTER-Net observations report
  24. GRB 240610A: Fermi GBM Final Real-time Localization
  25. IPN triangulation of GRB 240607A
  26. Fermi Gamma-ray Burst Monitor trigger 739632045/240609556 is not a GRB
  27. Fermi trigger No 739632045: Global MASTER-Net observations report
  28. Fermi GRB 240608A: Global MASTER-Net observations report
  29. Konus-Wind detection of GRB 240606B
  30. Fermi trigger No 739506569: Global MASTER-Net observations report
  31. GRB 240608A: Fermi GBM Final Real-time Localization
  32. Fermi GRB 240607A: Global MASTER-Net observations report
  33. GRB 240529A: NOEMA detection
  34. GRB 240607A: Fermi GBM Observation
  35. GRB 240606B: Fermi GBM Observation
  36. Swift Trigger 1235109: consistent with noise and not astrophysical
  37. GRB 240607A: AstroSat CZTI detection of bright long burst
  38. GRB 240607A: Fermi GBM detection of a very bright burst
  39. GRB 240529A: radio detection with AMI-LA
  40. GRB 240607A: BALROG localization (Fermi Trigger 739450879 / GRB 240607459)
  41. GRB 240607A: Fermi GBM Final Real-time Localization
  42. GRB 240606B: GECAM-B detection a long burst
  43. Fermi trigger No 739373591: Global MASTER-Net observations report
  44. GRB 240606B: Swift-XRT afterglow detection
  45. Swift GRB240606.15: Global MASTER-Net observations report
  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. LIGO/Virgo/KAGRA S240601co: Updated Sky localization
  56. GRB 240605C: Fermi GBM Final Real-time Localization
  57. IPN triangulation of GRB 240603A
  58. GRB 240605B: Fermi GBM Final Real-time Localization
  59. GRB 240604A: Fermi GBM Final Localization
  60. GRB 240605A: Fermi GBM Final Real-time Localization
  61. GRB 240604A: GECAM detection of a long burst
  62. GRB 240529A: SAO RAS optical observations
  63. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  64. Fermi GRB 240603C: Global MASTER-Net observations report
  65. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  66. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  67. GRB 240603A: Fermi GBM Final Localization
  68. GRB 240603C: BALROG localization (Fermi Trigger 739102156 / GRB 240603423)
  69. GRB 240603C: Fermi GBM Final Real-time Localization
  70. Swift Trigger 1232465: consistent with noise
  71. GRB 240603B: Swift detection of a possible burst
  72. GRB 240529A: MASTER prompt OT detection
  73. GRB 240603A: GECAM detection of a short burst
  74. GRB 240529A: continued SAO RAS optical observations
  75. Fermi GRB 240602A: Global MASTER-Net observations report
  76. GRB 240529A: OSN optical detection
  77. The EP-WXT source triggered on June 1st is likely a flaring star
  78. GRB 240529A: further SAO RAS optical observations
  79. LIGO/Virgo/KAGRA S240601aj: Updated Sky localization
  80. GRB 240602A: Fermi GBM Final Real-time Localization
  81. LIGO/Virgo/KAGRA S240601co: Identification of a GW compact binary merger candidate
  82. Swift Trigger 1232465 is not a GRB
  83. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  84. LIGO/Virgo/KAGRA S240530a: Updated Sky localization
  85. LXT 240528A: GSP optical upper limit
  86. GRB 240529A: 1.3m DFOT Optical observations
  87. LIGO/Virgo/KAGRA S240527en: Updated Sky localization
  88. LIGO/Virgo/KAGRA S240601aj: Identification of a GW compact binary merger candidate
  89. GRB 240531A: AstroSat CZTI detection of a short burst
  90. GRB 240529A : Mondy optical observations
  91. Konus-Wind detection of GRB 240529A
  92. IPN triangulation of the initial episode of GRB 240529A
  93. GRB 240529A: SAO RAS optical observations
  94. LIGO/Virgo/KAGRA S240531bp: Updated Sky localization
  95. LIGO/Virgo/KAGRA S240531bp: Identification of a GW compact binary merger candidate
  96. GRB 240529A: MAAO 0.7m telescope optical afterglow detection
  97. GRB 240529A: Insight-HXMT/HE detection
  98. GRB 240529A: optical photometry from Konkoly
  99. GRB 240529A: GROWTH-India optical follow-up
  100. GRB 240529A: T193/MISTRAL observations

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