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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"

11550 results found.

  1. Fermi GRB 210213A: Global MASTER-Net observations report
  2. GRB 210213A: Fermi GBM Final Real-time Localization
  3. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued CrAO and AbAO optical observations
  4. GRB 210204A: observations with the 3.6m Devasthal Optical Telescope and possible jet break
  5. GRB 210211A: Fermi GBM observation
  6. GRB 210210A as a BdHN II
  7. Fermi-LAT Gamma-ray Observations of IceCube-210210A
  8. GRB 210211A: Fermi GBM Final Real-time Localization
  9. Fermi trigger No 634659312: Global MASTER-Net observations report
  10. Fermi GRB 210210B: Global MASTER-Net observations report
  11. IceCube-210210A: Upper limits from Fermi-GBM Observations
  12. GRB 210210B: Fermi GBM Final Real-time Localization
  13. IceCube-210210A: IceCube observation of a high-energy neutrino candidate event
  14. ZTF21aahifke/AT2021clk: ZTF discovery of an optical fast transient (possible afterglow)
  15. GRB 210204A (ZTF21aagwbjr/AT2021buv): continued Mondy optical observations
  16. GRB 210204A: LBT observations and jet break
  17. GRB 210204A: redshift revision of ZTF21aagwbjr/AT2021buv (correction to GCN 29411)
  18. Fermi GRB 210207A: Global MASTER-Net observations report
  19. GRB 210207A: BALROG localization (Fermi Trigger / GRB 210207603)
  20. GRB 210204A (ZTF21aagwbjr/AT2021buv): Mondy and AbAO optical observations
  21. GRB 210207A: Fermi GBM Final Real-time Localization
  22. Konus-Wind detection of GRB 210204A / ZTF21aagwbjr
  23. GRB 210204A: Optical Observations from HCT
  24. GRB 210204A / ZTF21aagwbjr: Swift-XRT observations
  25. GRB 210204A: Swift ToO observations
  26. VLT/X-shooter redshift of 1.466 for ZTF21aagwbjr/AT2021buv, strengthening its association with GRB 210204A
  27. GRB 210204A: AstroSat CZTI Detection
  28. IPN triangulation of GRB 210204A
  29. ZTF21aagwbjr/AT2021buv: ZTF discovery of a fast optical transient likely associated with GRB 210104A
  30. Fermi GRB 210204B: Global MASTER-Net observations report
  31. Fermi GRB 210204A: Global MASTER-Net observations report
  32. GRB 210204B: Fermi GBM Final Real-time Localization
  33. GRB 210204: Fermi GBM observation
  34. GRB 210204A: GECAM detection
  35. GRB 210204A: BALROG localization (Fermi Trigger 634112970 / GRB 210204270)
  36. GRB 210204A: Fermi GBM Final Real-time Localization
  37. GRB 210202A: AGILE/MCAL detection
  38. Fermi GBM Observations of a bright burst from SGR J1935+2154
  39. GRB 210202A: Fermi GBM detection
  40. GRB 210202A: Fermi-LAT detection
  41. Fermi GRB 210202A: Global MASTER-Net observations report
  42. Fermi trigger No 633963272: Global MASTER-Net observations report
  43. Recent activity of SGR 1935+2154 as observed by CGBM
  44. GRB 210202A: BALROG localization (Fermi Trigger / GRB 210202841)
  45. GRB 210202A: Fermi GBM Final Real-time Localization
  46. Fermi trigger No 633879387: Global MASTER-Net observations report
  47. Fermi GBM Observations of SGR J1935+2154
  48. GRB 140330A: Swift-XRT refined Analysis
  49. GRB 140402A: Swift-XRT refined Analysis
  50. GRB 140104B: Swift-XRT refined Analysis
  51. GRB 210126A: AstroSat CZTI detection
  52. GRB 210123A: AstroSat CZTI detection
  53. GRB 210127A: Fermi GBM Final Real-time Localization
  54. GRB 210120A: Fermi GBM detection
  55. Fermi trigger No 633348010: Global MASTER-Net observations report
  56. GRB 210126A: GECAM detection
  57. GRB 210126A: BALROG localization (Fermi Trigger / GRB 210126417)
  58. Fermi trigger No 633257525: Global MASTER-Net observations report
  59. GRB 210123A: Fermi GBM Final Localization
  60. GRB 210120A : 1.3m DFOT optical observations
  61. GRB 210120A(MASTER OT J105242.66+152355.0 / AT2021axc): Mondy optical observations
  62. GRB 210120A: MASTER OT (possibly) discovery
  63. GECAM In-Flight Trigger of GRB 210120A
  64. Fermi GRB 210120A: Global MASTER-Net observations report
  65. GRB 210120A: BALROG localization (Fermi Trigger 632819449 / GRB 210120299)
  66. GRB 210120A: Fermi GBM Final Real-time Localization
  67. GECAM detection of a short GRB 210119A or a new SGR candidate Swift J1851.2-6148
  68. GRB 210119A: Insight-HXMT/HE detection
  69. GRB 210119A: Fermi GBM observation
  70. Short Fermi GRB 210119A or new SGR Swift J1851.2-6148: Possible MASTER Short OT detection
  71. Fermi GRB 210119A: Global MASTER-Net observations report
  72. GRB 210119A: Fermi GBM Final Real-time Localization
  73. GRB 200613A: Host galaxy redshift from OSIRIS/GTC
  74. GRB 210104A: Late-time CAHA 2.2m detection
  75. Fermi trigger No 632573937: Global MASTER-Net observations report
  76. GRB 210104A: AstroSat CZTI detection
  77. GRB 210104A: Mondy optical observations, light curve
  78. GRB 210104A: Assy continued optical observations, correction to GCN circ. 29265
  79. GRB 210108A: BALROG localization (Fermi Trigger 631793415 / GRB 210108424)
  80. GRB 210104A: SAO RAS optical observations
  81. GRB 201227A: ASIM observation
  82. GRB210104A: VIRT optical transient detection.
  83. GRB 210104A: SARA-KP 0.9m Optical Afterglow Detection
  84. Fermi trigger No 631602681: Global MASTER-Net observations report
  85. GRB 210104A: CALET Gamma-Ray Burst Monitor detection
  86. Fermi trigger No 631584650: Global MASTER-Net observations report
  87. GRB 210104A: Assy continued optical observations
  88. Fermi GRB 210105A: Global MASTER-Net observations report
  89. GRB 210105A: Fermi GBM Final Real-time Localization
  90. Konus-Wind detection of GRB 210104A
  91. GRB 210104A: 1.3m DFOT Optical Afterglow Detection
  92. GRB 210104A: MASTER OT rebrightening detection
  93. GRB 210104A: Fermi GBM detection
  94. GRB 210104A: MITSuME Ishigaki optical observation
  95. Fermi GRB 210104A: Global MASTER-Net observations report
  96. GRB 210104A: Assy optical observations
  97. GRB 210104A: MITSuME Akeno optical observation
  98. GRB 210104A: BOOTES-4/MET early optical afterglow detection
  99. GRB 210104A: BALROG localization (Fermi Trigger 631452424 / GRB 210104477)
  100. GRB 210104A: Fermi GBM Final Real-time Localization

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