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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"

11528 results found.

  1. GRB210410A: Joint inspection of RATIR and D50 data
  2. GRB 210410A: RATIR Optical and NIR Observations
  3. GRB 210410A: AGILE detection of a burst
  4. GRB 210410A: Fermi-LAT detection
  5. GRB210410A: Candidate optical afterglow by Ondrejov D50
  6. Fermi GRB 210410A: Global MASTER-Net observations report
  7. GRB 210410A: Swift XRT localization
  8. GRB 210410A: Fermi GBM Final Real-time Localization
  9. GRB 210406B: Fermi GBM detection
  10. Konus-Wind detection of GRB 210406A
  11. GRB 210406A: Fermi GBM detection
  12. GRB 210402A: MASTER prompt and follow up optical observation
  13. GRB 210402A: Fermi GBM detection
  14. GRB 210404.141: DDOTI Upper Limits
  15. GRB 210401A: GECAM detection
  16. Fermi trigger No 639199407: Global MASTER-Net observations report
  17. GRB 210402A: Montarrenti Observatory upper limit
  18. GRB 210328A: AstroSat CZTI detection
  19. Konus-Wind detection of GRB 210401A
  20. GRB 210402A: Swift detection of a burst
  21. Fermi trigger No 639093861: Global MASTER-Net observations report
  22. Fermi GRB 210401A: Global MASTER-Net observations report
  23. GRB 210401A: Fermi GBM Final Real-time Localization
  24. GRB 210328A: GECAM detection
  25. GRB 210324A: AstroSat CZTI detection
  26. GRB 210324C: AstroSat CZTI detection
  27. GRB 210328A: BALROG localization (Fermi Trigger / GRB 210328865)
  28. GRB 210328A: Fermi GBM Final Real-time Localization
  29. GRB 210326A: Insight-HXMT/HE detection
  30. GRB 210326A: Fermi GBM Final Localization
  31. Fermi trigger No 638414549: Global MASTER-Net observations report
  32. IPN triangulation of GRB 210324C
  33. GRB 210323A: Insight-HXMT/HE detection
  34. Fermi GRB 210324C: Global MASTER-Net observations report
  35. Fermi GRB 210324B: Global MASTER-Net observations report
  36. GRB 210323A: Gemini-North Optical Source Detection
  37. GRB 210324C: BALROG localization (Fermi Trigger 638308803 / GRB 210324833)
  38. GRB 210324C: Fermi GBM Final Real-time Localization
  39. Short GRB 210323A: GTC Observations
  40. GRB 210324B: Fermi GBM Final Real-time Localization
  41. Konus-Wind detection of GRB 210323A (short)
  42. GRB 210323A: Classification and redshift estimation
  43. GRB 210323A: Kitab optical upper limit
  44. GRB 210323A: Fermi GBM detection
  45. GRB 210324A: Fermi GBM Final Real-time Localization
  46. GRB 210323B: Swift/BAT-GUANO detection and possible arcminute localization
  47. Fermi GBM trigger 637977270/210320996 is not a GRB
  48. GRB 200524A: Redshift from Gemini-North
  49. GRB 210318B: Fermi GBM detection
  50. Fermi trigger No 637729731: Global MASTER-Net observations report
  51. Fermi GRB 210317A: Global MASTER-Net observations report
  52. GRB 210317A: GECAM detection
  53. GRB 210317A: Fermi GBM Final Real-time Localization
  54. Fermi trigger No 637521056: Global MASTER-Net observations report
  55. Fermi GRB 210312A: Global MASTER-Net observations report
  56. GRB 210312A: Fermi GBM Final Real-time Localization
  57. Konus-Wind detection of GRB 210308A
  58. Konus-Wind detection of GRB 210306A
  59. Konus-Wind detection of GRB 210305A
  60. Fermi trigger No 637027080: Global MASTER-Net observations report
  61. GRB 210306B: Fermi GBM detection
  62. Fermi trigger No 636926765: Global MASTER-Net observations report
  63. GRB 210305A: Fermi GBM observation
  64. GRB 210308A: Fermi GBM detection
  65. GRB 210306A: Fermi GBM observation
  66. GRB 210306A: Fermi-LAT detection
  67. GRB 210228B: Insight-HXMT/HE detection
  68. Fermi trigger No 636459103: Global MASTER-Net observations report
  69. Fermi trigger No 636187116: Global MASTER-Net observations report
  70. GRB 210228A: GECAM detection
  71. Fermi trigger No 636168178: Global MASTER-Net observations report
  72. GRB 210225A: Insight-HXMT/HE detection
  73. GRB 210226A: Fermi GBM detection
  74. Fermi trigger No 635922820: Global MASTER-Net observations report
  75. Fermi GBM Sub-Threshold Detection of GRB 210217A
  76. Fermi/GBM observation of a burst from SGR 1830-0645
  77. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued Assy and Mondy optical observations
  78. GRB 210211A: ePESSTO+ NTT optical observations
  79. Fermi GRB 210213A: Global MASTER-Net observations report
  80. GRB 210213A: Fermi GBM Final Real-time Localization
  81. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued CrAO and AbAO optical observations
  82. GRB 210204A: observations with the 3.6m Devasthal Optical Telescope and possible jet break
  83. GRB 210211A: Fermi GBM observation
  84. GRB 210210A as a BdHN II
  85. Fermi-LAT Gamma-ray Observations of IceCube-210210A
  86. GRB 210211A: Fermi GBM Final Real-time Localization
  87. Fermi trigger No 634659312: Global MASTER-Net observations report
  88. Fermi GRB 210210B: Global MASTER-Net observations report
  89. IceCube-210210A: Upper limits from Fermi-GBM Observations
  90. GRB 210210B: Fermi GBM Final Real-time Localization
  91. IceCube-210210A: IceCube observation of a high-energy neutrino candidate event
  92. ZTF21aahifke/AT2021clk: ZTF discovery of an optical fast transient (possible afterglow)
  93. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued Mondy optical observations
  94. GRB 210204A: LBT observations and jet break
  95. GRB 210204A: redshift revision of ZTF21aagwbjr/AT2021buv (correction to GCN 29411)
  96. Fermi GRB 210207A: Global MASTER-Net observations report
  97. GRB 210207A: BALROG localization (Fermi Trigger / GRB 210207603)
  98. GRB 210204A (ZTF21aagwbjr/AT2021buv): Mondy and AbAO optical observations
  99. GRB 210207A: Fermi GBM Final Real-time Localization
  100. Konus-Wind detection of GRB 210204A / ZTF21aagwbjr

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