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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

14986 results found.

  1. GRB 210226A: Fermi GBM detection
  2. GRB 210218A: Swift-XRT confirmation of afterglow
  3. GRB 210226A: Swift detection of a burst
  4. Konus-Wind detection of GRB 210222A
  5. GRB 210222B: VIRT optical detection
  6. GRB 210222B: Swift/UVOT Detection
  7. GRB 210222B: FRAM-ORM afterglow detection
  8. GRB 210217A: Swift/UVOT Detection
  9. GRB 210222B: MASTER OT observation
  10. GRB 210222A: CALET Gamma-Ray Burst Monitor detection
  11. GRB 210222B: GOTO confirmation of afterglow detection (correction to GCN29548)
  12. GRB 210222B: Liverpool Telescope optical detection
  13. GRB 210222B: GOTO confirmation of afterglow detection
  14. GRB210222B: LCO Optical Afterglow Detection
  15. GRB210222B: BOOTES-1 optical afterglow detection
  16. GRB 210222B: Swift detection of a burst with an optical counterpart
  17. GRB 210222A: MAXI/GSC detection
  18. uGMRT radio detection of GRB 210204A
  19. GRB 210217A: 1.3m DFOT optical detection
  20. Fermi GBM Sub-Threshold Detection of GRB 210217A
  21. GRB 210218A: Swift detection of a burst
  22. GRB 210217A: Swift detection of a burst with an optical counterpart
  23. IceCube-210210A: Two Additional Optical Candidate Counterparts Found by DECam
  24. GRB 210208A: 1.3m DFOT Optical upper limit
  25. GRB 210210A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  26. Swift Trigger 1033144: Detection of SGR 1830-0645
  27. Konus-Wind detection of GRB 210212B / ZTF21aakruew
  28. GRB 210213B: Insight-HXMT/HE detection
  29. ZTF21aakruew/AT2021cwd: ZTF and LT discovery of a hostless, red, and rapidly fading optical transient
  30. IceCube alert 134994_1103075 retraction
  31. GRB 210213A: Fermi GBM Final Real-time Localization
  32. IceCube-210210A: Four Candidate Optical Counterparts from DECam Observations
  33. Swift Trigger 1032350: Detection of SGR 1830-0645
  34. GRB 210212A: BOOTES-4/MET optical upper limit
  35. GRB 210204A: observations with the 3.6m Devasthal Optical Telescope and possible jet break
  36. GRB 210212A: Swift detection of a burst
  37. GRB 210207B: GECAM detection
  38. GRB 210211A: Swift/UVOT Detection
  39. GRB 210210A: CAHA detection and likely jet break
  40. IceCube-210210A: No neutrino counterpart in ANTARES
  41. GRB 210211A: REM optical/NIR afterglow detection
  42. GRB 210211A: Swift detection of a burst
  43. GRB 210211A: Fermi GBM Final Real-time Localization
  44. GRB 210210A: FRAM-ORM afterglow detection
  45. GRB 210210B: Fermi GBM Final Real-time Localization
  46. GRB 210209A: BOOTES-4/MET optical upper limit
  47. GRB 210210A: LCO Optical Afterglow Detection
  48. GRB 210210A: Swift/UVOT Detection
  49. GRB 210112A: LBT host detection and correction to GCN 29319 (CAHA observations)
  50. IceCube-210210A: IceCube observation of a high-energy neutrino candidate event
  51. GRB 210210A: Redshift from OSIRIS/GTC
  52. GRB 210210A: MASTER afterglow observation
  53. ZTF21aahifke/AT2021clk: ZTF discovery of an optical fast transient (possible afterglow)
  54. GRB 210210A: Swift detection of a burst with an optical counterpart
  55. GRB 210209A: Swift detection of a burst
  56. GRB 210207B: Continued LCO Observations
  57. GRB 210208A: BOOTES-2/TELMA optical upper limit
  58. GRB 210207B: AstroSat CZTI detection
  59. GRB 210207B: Swift/UVOT Detection
  60. GRB 210207B: Insight-HXMT/HE detection
  61. GRB 210204A: LBT observations and jet break
  62. GRB 210207B: LCO Optical Afterglow Detection
  63. Konus-Wind detection of GRB 210207B
  64. SGR 1935+2154: MAXI/GSC detection
  65. Konus-Wind detection of GRB 210204A (correction to GCN 29415)
  66. GRB 210207B: AbAO optical upper limit
  67. GRB 210207B: optical detection with 3.6m Devasthal Optical Telescope
  68. GRB 210207B: Swift detection of a burst with a bright optical counterpart
  69. GRB 210207A: Fermi GBM Final Real-time Localization
  70. Konus-Wind detection of GRB 210204A / ZTF21aagwbjr
  71. VLT/X-shooter redshift of 1.466 for ZTF21aagwbjr/AT2021buv, strengthening its association with GRB 210204A
  72. GRB 210204A: AstroSat CZTI Detection
  73. IPN triangulation of GRB 210204A
  74. GRB 210205B: AGILE/MCAL detection of a burst
  75. GRB 210205A: BOOTES-4/MET optical upper limit
  76. GRB 210205A: Swift detection of a burst
  77. GRB 210204B: Fermi GBM Final Real-time Localization
  78. GRB 210204A: GECAM detection
  79. GRB 210204A: Fermi GBM Final Real-time Localization
  80. GRB 210202A: AGILE/MCAL detection
  81. GRB 210202A: Fermi GBM detection
  82. GRB 210202A: Fermi-LAT detection
  83. INTEGRAL detection of a short burst from SGR 1935+2154
  84. GRB 210202A: Fermi GBM Final Real-time Localization
  85. GRB 210131A: GECAM detection
  86. GECAM observations of SGR 1935+2154
  87. GRB 210129A: Insight-HXMT/HE detection
  88. Konus-Wind detection of two bright bursts from SGR 1935+2154
  89. GRB 210126A: AstroSat CZTI detection
  90. GRB 210124B: AstroSat CZTI detection
  91. GRB 210123A: AstroSat CZTI detection
  92. IPN triangulation of a bright burst from SGR 1935+2154
  93. GECAM detection of a short burst probably from SGR 1935+2154
  94. GRB 210127A: Fermi GBM Final Real-time Localization
  95. GRB 210120A: Fermi GBM detection
  96. Konus-Wind detection of GRB 210121A
  97. Konus-Wind detection of GRB 210124B
  98. GRB 210126A: GECAM detection
  99. IPN triangulation of GRB 210124B (short)
  100. GRB 210124B: Insight-HXMT/HE detection

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