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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"

11519 results found.

  1. IPN triangulation of GRB 221022B (long)
  2. GRB 221022B: AstroSat CZTI detection
  3. GRB 221022A: Fermi GBM detection
  4. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  5. GRB 221023A: Fermi-LAT detection
  6. GRB 221022B: Fermi GBM detection
  7. GRB 221021A: Fermi GBM observation
  8. GRB 221009A: Determination of the black holes mass and spin
  9. GRB 221023A: Fermi GBM Final Localization
  10. GRB 221022A: Swift/BAT-GUANO detection
  11. GRB 221022B: Swift/BAT-GUANO detection outside the coded FOV
  12. GRB 221022B: AGILE detection
  13. GRB 221009A: James Webb Space Telescope Observations
  14. GRB 221022B: Fermi GBM Final Real-time Localization
  15. GRB 221009A: Analysis of the initial episode using data of GBM/Fermi and SPI-ACS/INTEGRAL
  16. GRB 221021A: Swift/BAT-GUANO detection outside the coded FOV
  17. GRB 221022A: Fermi GBM Final Real-time Localization
  18. GRB 221020A: Detection by GRBAlpha
  19. SGR 1935+21542: VZLUSAT-2 and GRBAlpha joint detection
  20. GRB 221021A: Fermi GBM Final Real-time Localization
  21. Fermi GBM trigger 687320613 / 221013100 (GRB 221013B) is not a GRB
  22. GRB 221009A: Peak luminosity of the supernova vs. synchrotron afterglow
  23. GRB 221020A: Fermi GBM Final Real-time Localization
  24. Improved IPN localization for GRB 221009A (BepiColombo-MGNS light curve)
  25. GRB 221009A: TNG NIR detection
  26. GRB 221009A: BOAO NIR detections
  27. GRB 221009A X-ray light-curve and the indication of TeV light-curve
  28. GRB 221009A: Spectroscopic detection of emerging SN features
  29. GRB 221013B: Swift/BAT-GUANO detection
  30. SGR 1935+2154: Bursting activity detected by VZLUSAT-2
  31. AGILE detection of the 2022 October 17 burst from SGR J1935+2154 reported by Konus-Wind
  32. GRB 221009A: GRANDMA observations
  33. SGR 1935+2154: Detection by GRBAlpha
  34. The probability of observing GRB 221009A at z = 0.151
  35. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  36. Konus-Wind detection of GRB 221016A
  37. GRB 221016A: Fermi GBM observation
  38. GRB 221009A: A type I BdHN of exceptional energetics
  39. GRB 221016A: Fermi GBM Final Real-time Localization
  40. GRB 221009A: LEIA X-ray Afterglow Detection
  41. GRB 221009A: VLT spectroscopic detection of the host galaxy
  42. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  43. GRB 221009A: Armchair Energetics
  44. GRB 221009A: Fermi LAT data rate effects due to extremely high flux
  45. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
  46. GRB 221009A: continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve
  47. GRB 221009A: HEBS detection
  48. GRB 221009A: a 397.7 GeV photon observed by Fermi-LAT at 0.4 day after the GBM trigger
  49. GRB 221014A: Fermi GBM Final Real-time Localization
  50. GRB 221009A: Gamma-ray Detection by SIRI-2
  51. GRB 221009A: search for neutrinos with KM3NeT
  52. Fermi Gamma-ray Burst Monitor continues to detect SGR 1935+2154
  53. Fermi trigger No 687345829: Global MASTER-Net observations report
  54. Fermi trigger No 687344475: Global MASTER-Net observations report
  55. Fermi trigger No 687340841: Global MASTER-Net observations report
  56. Fermi trigger No 687337536: Global MASTER-Net observations report
  57. GRB 221009A: Sayan observatory 1.6-m telescope observations
  58. Fermi trigger No 687281393: Global MASTER-Net observations report
  59. GRB 221013B: Fermi GBM Final Real-time Localization
  60. GRB 221013A: Fermi GBM Final Real-time Localization
  61. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  62. Fermi trigger No 687205006: Global MASTER-Net observations report
  63. GRB 220826B: Detection by GRBAlpha
  64. GRB 221009A: NuSTAR Detection
  65. GRB 221009A: NICER follow-up observations
  66. GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
  67. Fermi trigger No 687190301: Global MASTER-Net observations report
  68. Fermi Gamma-ray Burst Monitor trigger 221011452/687178284 is not a GRB
  69. GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
  70. GRB 221009A: Detection by GRBAlpha
  71. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  72. GRB 221011A: Fermi GBM Final Real-time Localization
  73. GRB 221009A: BlackGEM optical observations
  74. LHAASO observed GRB 221009A with more than 5000 VHE photons up to around 18 TeV
  75. GRB 221009A: NOEMA mm detection
  76. Fermi trigger No 687077239: Global MASTER-Net observations report
  77. Konus-Wind detection of GRB 221009A
  78. GRB 221009A: Lulin SLT-40cm optical observations
  79. GRB 221009A: Upper limits from a neutrino search with IceCube
  80. GRB221009A/Swift J1913.1+1946: SRG/ART-XC observation
  81. GRB 221009A / Swift J1913.1+1946: GIT detection of the optical afterglow
  82. GRB 221009A: Fermi-LAT refined analysis
  83. GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
  84. GRB 221009: Swift/UVOT Detection
  85. GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection
  86. GRB 221009A: REM optical and NIR detection of the afterglow
  87. GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
  88. GRB 221009A: Redshift from X-shooter/VLT
  89. GRB 221009A (Swift J1913.1+1946): Mondy optical observations
  90. GRB 221009A BOOTES-2/TELMA and OSN optical detections
  91. GRB 221009A: Fermi GBM observation
  92. IPN triangulation of extremely bright GRB 221009A
  93. Fermi trigger No 687014224: Global MASTER-Net observations report
  94. GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection
  95. GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB
  96. GRB 221009A: Swift detected transient may be GRB
  97. GRB 220915A: Detection by GRBAlpha
  98. GRB 220912A: Detection by VZLUSAT-2
  99. Fermi trigger No 686588176: Global MASTER-Net observations report
  100. GRB220927A: Detection by GRBAlpha

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