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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"

11550 results found.

  1. GRB 170109A: POLAR Observation
  2. LIGO/Virgo G268556: DESGW/DECam observations
  3. LIGO/Virgo G268556: Fermi-LAT search for high-energy gamma-ray counterpart
  4. LIGO/Virgo G268556: Fermi GBM Observations
  5. GRB 170101B: POLAR observation
  6. GRB 161228C: POLAR observation
  7. GRB 161229A: POLAR observation
  8. GRB 170101B: Astrosat CZTI detection
  9. GRB 170101B: Fermi GBM detection
  10. GRB 161228B: POLAR Observation
  11. GRB 161228A: POLAR Observation
  12. Fermi GBM trigger 504490076/161227005 is not a GRB
  13. Fermi GBM trigger 504233075/161224301 is not a GRB
  14. Fermi GBM trigger 504061556/161222046 is not a GRB
  15. Fermi GBM trigger 504043585/161221838 is not a GRB
  16. GRB 161218B: Astrosat CZTI detection
  17. Fermi GBM trigger 503982114/161221126 is not a GRB
  18. GRB 161217B: POLAR Observation
  19. Konus-Wind observation of GRB 161218B
  20. IPN Triangulation of GRB 161218B (long/very bright)
  21. GRB 161212A: POLAR Detection
  22. GRB 161218B: POLAR observation
  23. GRB 161218A: POLAR observation
  24. GRB 161218B: Fermi GBM detection
  25. GRB 161207A: POLAR observation
  26. GRB 161213A: POLAR Observation
  27. GRB 161207B: POLAR observation
  28. GRB 161205A: POLAR observation
  29. GRB 161210A: POLAR observation
  30. Fermi-LAT Gamma-ray Observations of IceCube-161210
  31. GRB 161207A: CALET Gamma-Ray Burst Monitor detection
  32. GRB 161206A: Fermi GBM detection
  33. Konus-Wind observation of GRB 161202A
  34. MASTER: Optical Blazar Flare Detection during Fermi trigger 502272781 inspection
  35. GRB 161129A: POLAR Detection
  36. GRB 161202A: Fermi-LAT detection
  37. Fermi GBM trigger 502258294/161201175 is not a GRB
  38. Fermi Gamma-ray Burst Monitor trigger 161130183 is not a GRB
  39. GRB 161129A: Fermi GBM Detection
  40. Fermi GBM trigger 501785179/161125699 is not a GRB
  41. Fermi GBM trigger 501779084/161125628 is not a GRB
  42. GRB 161119A: MASTER-SAAO possible OT detection during Fermi Alert
  43. Konus-Wind observation of GRB 161117A
  44. GRB 161117A: Fermi GBM detection/observation
  45. GRB 161109A: Swift/UVOT Upper Limits
  46. GRB 161109A: Swift-XRT observations
  47. GRB 161109A: Tiled Swift observations
  48. GRB 161109A: Fermi GBM observation
  49. GRB 161109A: Fermi-LAT detection
  50. GRB 161106A: Lomonosov BDRG gamma ray discovery
  51. Fermi LAT Gamma-ray Observations of IceCube-161103
  52. GRB 161106A: Fermi GBM detection
  53. Fermi GBM Observations of IceCube-161103
  54. GRB 160928A: The first GRB detected by POLAR
  55. GRB 161020A: Fermi GBM observation
  56. Fermi GBM trigger 499467682/161029876 is not a GRB
  57. GRB 161015A: 15 GHz upper limits from AMI
  58. GRB 161022A: Fermi GBM observation
  59. IPN Triangulation of GRB 161020B
  60. GRB 161020A: A long GRB detected by INTEGRAL
  61. GRB 161015A: further Swift-XRT follow-up observations
  62. Konus-Wind observation of GRB 161017A
  63. GRB 161017A: GTC additional spectroscopy and refined redshift
  64. GRB 161017A: Fermi GBM observation
  65. GRB 161015A: Swift/UVOT observations
  66. Konus-Wind observation of GRB 161015A
  67. GRB161015A: AstroSat CZTI detection
  68. Konus-Wind observation of GRB 161014A
  69. GRB 161015A: Swift-XRT observations
  70. GRB 161015A: Fermi GBM detection
  71. GRB 161015A: Tiled Swift observations
  72. GRB 161015A: Fermi-LAT detection
  73. GRB 161014A: Fermi GBM observation
  74. GRB 161014A: Swift detection of a burst
  75. GRB 160925A: Kottamia R-band observation
  76. Konus-Wind observation of GRB 161004B
  77. GRB 161004B: Fermi GBM detection
  78. GRB 160917B: Lomonosov BDRG gamma ray discovery
  79. Konus-Wind observation of GRB 161001A (short/hard ?)
  80. GRB 161001A: Fermi GBM detection
  81. Fermi GBM trigger 496791348/160928900 is not a GRB
  82. GRB160910A: AstroSat CZTI detection
  83. XRT refined analysis for GRB 160925A
  84. GRB 160925A/MASTER optical transient: Mondy optical observations
  85. GRB 160925A: Bassano Bresciano Photometry of MASTER optical transient
  86. GRB 160925A: Optical spectroscopy of MASTER optical transient
  87. GRB160824B: AstroSat CZTI detection
  88. GRB 160925A / Fermi 496473540: MASTER OT observations
  89. GRB 160925A: Swift ToO observations
  90. GRB160925A / Fermi 496473540: MASTER optical transient confirmation by LCOGT-FTN
  91. GRB 160925A / Fermi 496473540: Global MASTER Net OT discovery
  92. GRB 160910A: 15 GHz detection from AMI
  93. GRB 160917A: Fermi GBM observation
  94. GRB 160910A: Swift/UVOT Detection
  95. GRB 160912A: Fermi GBM detection
  96. GRB 160910A: Global MASTER Net OT detection before LAT alert
  97. Konus-Wind observation of GRB 160910A
  98. GRB 160910A: NOT afterglow confirmation
  99. GRB 160910A: Tiled Swift observations
  100. GRB 160910A: Swift-XRT afterglow detection

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