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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"

27973 results found.

  1. GRB 210218A: NEXT optical upper limit
  2. GRB 210218A: Swift detection of a burst
  3. GRB 210205A: observations with the 3.6m DOT, a potential dark burst?
  4. GRB 210217A: Enhanced Swift-XRT position
  5. Fermi/GBM observation of a burst from SGR 1830-0645
  6. GRB 210217A: NEXT early optical afterglow observations
  7. GRB 210217A: Swift detection of a burst with an optical counterpart
  8. IceCube-210210A: Two Additional Optical Candidate Counterparts Found by DECam
  9. GRB 210208A: 1.3m DFOT Optical upper limit
  10. GRB 210210A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  11. Swift Trigger 1033144: Detection of SGR 1830-0645
  12. Konus-Wind detection of GRB 210212B / ZTF21aakruew
  13. GRB 210212B: Swift ToO observations
  14. IPN triangulation of GRB 210212B (consistent with ZTF21aakruew/AT2021cwd)
  15. GRB 210212A: 1.3m DFOT Optical upper limit
  16. GRB 210213B: Insight-HXMT/HE detection
  17. ZTF21aakruew/AT2021cwd: ZTF and LT discovery of a hostless, red, and rapidly fading optical transient
  18. GRB 210212A: Gemini South optical observations
  19. IceCube alert 134994_1103075 retraction
  20. GRB 210213A: Fermi GBM Final Real-time Localization
  21. IceCube-210210A: Four Candidate Optical Counterparts from DECam Observations
  22. Swift Trigger 1032350: Detection of SGR 1830-0645
  23. GRB 210212A: Possible host galaxy counterpart with the NOT
  24. Swift GRB 210212A: Global MASTER-Net observations report
  25. GRB 210212A: MITSuME Akeno optical upper limits
  26. GRB 210212A: Swift-XRT refined Analysis
  27. GRB 210212A: BOOTES-4/MET optical upper limit
  28. GRB 210212A: Swift/UVOT Upper Limits
  29. GRB 210212A: Swift-BAT refined analysis
  30. GRB 210204A: observations with the 3.6m Devasthal Optical Telescope and possible jet break
  31. GRB 210212A: Enhanced Swift-XRT position
  32. GRB 210212A: Swift detection of a burst
  33. GRB 210207B: GECAM detection
  34. GRB 210211A: Swift/UVOT Detection
  35. GRB 210211A: Swift-XRT refined Analysis
  36. GRB 210211A: Swift-BAT refined analysis
  37. GRB 210211A: Fermi GBM observation
  38. Swift-XRT observations of IceCube-210210A
  39. GRB 210209A: Swift-BAT refined analysis
  40. GRB 210211A: Enhanced Swift-XRT position
  41. GRB 210211A: MASTER optical observation of REM OT
  42. GRB 210210A: CAHA detection and likely jet break
  43. IceCube-210210A: No neutrino counterpart in ANTARES
  44. GRB 210211A: REM optical/NIR afterglow detection
  45. GRB 210211A: Swift detection of a burst
  46. Swift GRB210211.36: Global MASTER-Net observations report
  47. GRB 210211A: Fermi GBM Final Real-time Localization
  48. GRB 210210A: FRAM-ORM afterglow detection
  49. GRB 210210A: Swift-BAT refined analysis
  50. GRB 210210B: Fermi GBM Final Real-time Localization
  51. GRB 210209A: BOOTES-4/MET optical upper limit
  52. GRB 210210A: LCO Optical Afterglow Detection
  53. Swift GRB 210209A: Global MASTER-Net observations report
  54. GRB 210210A: Swift/UVOT Detection
  55. GRB 210112A: LBT host detection and correction to GCN 29319 (CAHA observations)
  56. GRB 210209A: MITSuME Akeno optical upper limits
  57. IceCube-210210A: IceCube observation of a high-energy neutrino candidate event
  58. GRB 210209A: Swift/UVOT Upper Limits
  59. GRB 210210A: Swift-XRT refined Analysis
  60. GRB 210210A: Redshift from OSIRIS/GTC
  61. GRB 210209A: Swift-XRT refined Analysis
  62. GRB 210210A: Enhanced Swift-XRT position
  63. GRB 210210A: MASTER afterglow observation
  64. ZTF21aahifke/AT2021clk: ZTF discovery of an optical fast transient (possible afterglow)
  65. Swift GRB 210210A: Global MASTER-Net observations report
  66. GRB 210210A: Swift detection of a burst with an optical counterpart
  67. GRB 210209A: Enhanced Swift-XRT position
  68. GRB 210209A: Swift detection of a burst
  69. GRB 210207B: Continued LCO Observations
  70. GRB 210208A: BOOTES-2/TELMA optical upper limit
  71. GRB 210207B: AstroSat CZTI detection
  72. GRB 210207B: Swift/UVOT Detection
  73. GRB 210207B: Swift-BAT refined analysis
  74. GRB 210207B: Insight-HXMT/HE detection
  75. GRB 210204A: LBT observations and jet break
  76. GRB 210207B: LCO Optical Afterglow Detection
  77. GRB 210207B: KAIT Optical Observations
  78. GRB 210207B: AGILE observations
  79. GRB 210207B: Swift-XRT refined Analysis
  80. Konus-Wind detection of GRB 210207B
  81. SGR 1935+2154: MAXI/GSC detection
  82. Konus-Wind detection of GRB 210204A (correction to GCN 29415)
  83. GRB 210207B: AbAO optical upper limit
  84. GRB 210207B: Enhanced Swift-XRT position
  85. GRB 210207B: optical detection with 3.6m Devasthal Optical Telescope
  86. GRB 210207B: Swift detection of a burst with a bright optical counterpart
  87. GRB 210207A: Fermi GBM Final Real-time Localization
  88. Konus-Wind detection of GRB 210204A / ZTF21aagwbjr
  89. GRB 210204A / ZTF21aagwbjr: Swift-XRT observations
  90. GRB 210204A: Swift ToO observations
  91. VLT/X-shooter redshift of 1.466 for ZTF21aagwbjr/AT2021buv, strengthening its association with GRB 210204A
  92. GRB 210204A: AstroSat CZTI Detection
  93. GRB 210205A: Swift-BAT refined analysis
  94. IPN triangulation of GRB 210204A
  95. GRB 210205A: Swift-XRT refined Analysis
  96. GRB 210205A: MITSuME Ishigaki optical observation
  97. GRB 210205B: AGILE/MCAL detection of a burst
  98. GRB 210205A: Swift/UVOT Upper Limits
  99. Swift GRB 210205A: Global MASTER-Net observations report
  100. GRB 210205A: BOOTES-4/MET optical upper limit

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