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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"

3039 results found.

  1. GRB 201104B: Swift/UVOT Detection
  2. GRB 201104A: Fermi GBM observation
  3. Fermi trigger No 625695596: Global MASTER-Net observations report
  4. Fermi GRB 201020B: Global MASTER-Net observations report
  5. GRB 201020A: Swift detection of a burst with an optical counterpart.
  6. Konus-Wind observation of GRB 201013A
  7. SGR 1830-0645: Swift-BAT refined analysis
  8. GRB 201006A: Chandra upper limit on the X-ray afterglow
  9. Baksan Neutrino Observatory Alert 201006.88: Global MASTER-Net observations report
  10. GRB 201006A: Swift detection of a burst
  11. Fermi trigger No 623470566: Global MASTER-Net observations report
  12. Fermi trigger No 623493962: Global MASTER-Net observations report
  13. Swift-XRT observations of IceCube 200929A
  14. GRB 200928A: Fermi GBM Final Localization
  15. Fermi GRB 200925A: Global MASTER-Net observations report
  16. GRB 200923A: Fermi GBM Final Real-time Localization
  17. GRB 200922A: Swift-BAT refined analysis
  18. Fermi GRB 200914A: Global MASTER-Net observations report
  19. Fermi GRB 200909A: Global MASTER-Net observations report
  20. GRB 200907C: Fermi GBM Final Real-time Localization
  21. GRB 200906A: EMIR/GTC NIR upper limit
  22. GRB 200906A: LBT near-infrared upper limit
  23. Fermi GRB 200903C: Global MASTER-Net observations report
  24. GRB 200903A: Swift-BAT refined analysis
  25. Fermi GRB 200903B: Global MASTER-Net observations report
  26. Swift GRB200903.03: Global MASTER-Net observations report
  27. GRB 200901B: Swift-BAT refined analysis
  28. GRB 200829A: Kitab optical upper limit
  29. Zwicky Transient Facility discovery of ZTF20abtxwfx/AT2020sev, a fast optical transient and candidate afterglow
  30. IPN triangulation of GRB 200826B
  31. Fermi GRB 200824A: Global MASTER-Net observations report
  32. GRB 200815A: MASTER optical observations
  33. Baksan Neutrino Observatory Alert 200819.09: Global MASTER-Net observations report
  34. GRB 200818A: Fermi GBM Final Localization
  35. Fermi trigger No 619487843: Global MASTER-Net observations report
  36. Fermi GRB 200809B: Global MASTER-Net observations report
  37. GRB 200808A: Fermi GBM Final Real-time Localization
  38. GRB 200806A: Swift-BAT refined analysis
  39. GRB 200806A: MITSuME Akeno optical upper limits
  40. AX J1846.4-0258: Swift-BAT refined analysis
  41. Fermi GRB 200801A: Global MASTER-Net observations report
  42. GRB 200716C: Kitab optical observations
  43. Konus-Wind observation of GRB 200716C: correction to GCN 28147
  44. Konus-Wind observation of GRB 200716C
  45. GRB 200716C: Insight-HXMT/HE detection
  46. GRB 200716C: CALET Gamma-Ray Burst Monitor detection
  47. GRB 200716C: Swift-BAT refined analysis
  48. GRB 200716C: Fermi GBM detection
  49. GRB 200716C: AGILE/MCAL detection
  50. GRB 200716C: Fermi-LAT detection
  51. GRB 200716C: Swift detection of a burst with an optical counterpart
  52. GRB 200716C: Fermi GBM Final Real-time Localization
  53. Fermi GRB 200714D: Global MASTER-Net observations report
  54. Fermi GRB 200714A: Global MASTER-Net observations report
  55. Fermi-LAT-ANTARES 200407a Coincidence
  56. Fermi GRB 200702A: Global MASTER-Net observations report
  57. Fermi GRB 200626A: Global MASTER-Net observations report
  58. Fermi GRB 200625A: Global MASTER-Net observations report
  59. Fermi GRB 200623A: Global MASTER-Net observations report
  60. Fermi trigger No 614103490: Global MASTER-Net observations report
  61. Baksan Neutrino Observatory Alert 200617.47: Global MASTER-Net observations report
  62. LIGO/Virgo MS200614bz: Test Identification of a binary neutron star candidate
  63. GRB 200615B: MAXI/GSC detection
  64. IceCube Alert 200615.62: Global MASTER-Net observations report
  65. Fermi GRB 200615A: Global MASTER-Net observations report
  66. Baksan Neutrino Observatory Alert 200614.34: Global MASTER-Net observations report
  67. Fermi GRB 200613A: Global MASTER-Net observations report
  68. Fermi GRB 200607A: Global MASTER-Net observations report
  69. IPN triangulation of GRB 200605A (short)
  70. 1RXS J1708−4009: Swift-BAT refined analysis
  71. Fermi GRB 200604A: Global MASTER-Net observations report
  72. Fermi GRB 200601A: Global MASTER-Net observations report
  73. GRB 200528A: Swift-BAT refined analysis
  74. Swift GRB 200528A: Global MASTER-Net observations report
  75. GRB 200524A: Correction to the GCN 27800
  76. GRB 200524A: GROWTH-India confirmation of optical afterglow
  77. IceCube Alert 200523.10: Global MASTER-Net observations report
  78. Fermi GRB 200522B: Global MASTER-Net observations report
  79. GRB 200519A: BOOTES-3/YA optical counterpart observations
  80. GRB 200519A: Swift detection of a burst with an optical afterglow
  81. Fermi trigger No 611434353: Global MASTER-Net observations report
  82. GRB 200517A: MAXI/GSC detection
  83. Swift J1818.0-1607: BOOTES-3/YA optical upper limit
  84. Baksan Neutrino Observatory Alert 200512.: Global MASTER-Net observations report
  85. SGR 1935+2154: MASTER optical observations
  86. high bursting activity of SGR 1935+2154: CGBM observations
  87. SGR 1935+2154 the Insight-HXMT observation plan
  88. Fermi GRB 200423A: Global MASTER-Net observations report
  89. Fermi GRB 200421A: Global MASTER-Net observations report
  90. Fermi trigger No 608935505: Global MASTER-Net observations report
  91. Fermi GRB 200415A: Global MASTER-Net observations report
  92. GRB 200412A : AstroSat CZTI detection
  93. IPN triangulation of GRB 200415A (possible Magnetar Giant Flare in Sculptor Galaxy?)
  94. Konus-Wind observation of GRB 200412A
  95. GRB 200412B: contunued AbAO optical observations
  96. IPN triangulation of GRB 200412A
  97. GRB 200412A: Fermi GBM detection
  98. GRB 200412A: BALROG localization (Fermi Trigger 608367436 / GRB 200412290)
  99. GRB 200410A: Swift/UVOT Detection
  100. Fermi trigger No 608204639: Global MASTER-Net observations report

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