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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"

21093 results found.

  1. Swift GRB240101.85: Global MASTER-Net observations report
  2. Fermi trigger No 725806648: Global MASTER-Net observations report
  3. GRB 231230A: GOTO optical upper limits
  4. GRB 231230A: Swift/UVOT Upper Limits
  5. GRB 231230A: NOT optical upper limits
  6. Fermi trigger No 725592555: Global MASTER-Net observations report
  7. Swift GRB231230.06: Global MASTER-Net observations report
  8. Fermi trigger No 725143760: Global MASTER-Net observations report
  9. GRB 231222B: Swift-XRT afterglow detection
  10. Fermi trigger No 724921799: Global MASTER-Net observations report
  11. LAT GRB231222.31: Global MASTER-Net observations report
  12. GRB 231222A: Tiled Swift observations
  13. IceCube-231211A: GRANDMA observations of PKS2047+098
  14. GRB 231220A: Swift-XRT follow-up observations
  15. GRB 231220A: Swift ToO observations
  16. GRB 231220A: Swift/BAT-GUANO arcminute localization of a long burst
  17. Fermi trigger No 724781422: Global MASTER-Net observations report
  18. GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
  19. Fermi trigger No 724698747: Global MASTER-Net observations report
  20. GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
  21. GRB 231216A: optical upper limits from the INAF Asiago Observatory
  22. GRB 231215A: AMI-LA radio detection
  23. GRB 231216A: Nanshan/HMT optical upper limit
  24. GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
  25. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  26. GRB 231216A: REM NIR upper limits
  27. GRB 231216A: Swift/UVOT Upper Limits
  28. GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
  29. GRB 231216A: GIT optical upper limit
  30. GRB 231216A: NOT optical upper limits
  31. Swift GRB231216.77: Global MASTER-Net observations report
  32. GRB 231215A: optical afterglow detection from the INAF Asiago Observatory
  33. GRB 231215A: NOT optical observations
  34. GRB 231214A: Swift/UVOT Upper Limits
  35. GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
  36. GRB 231215A : OHP/T193 optical afterglow detection
  37. GRB 231215A: Swift/UVOT Detection
  38. ATCA observations of GRB 231210B
  39. Fermi trigger No 724326442: Global MASTER-Net observations report
  40. GRB 231214A: REM optical/NIR upper limits
  41. GRB 231215A : Nanshan/HMT optical observations
  42. GRB 231215C: MASTER OT detection
  43. Swift GRB231215.41: Global MASTER-Net observations report
  44. GRB 231215A: Swift-XRT observations
  45. Fermi trigger No 724278269: Global MASTER-Net observations report
  46. Fermi trigger No 724233240: Global MASTER-Net observations report
  47. Swift GRB231214.85: Global MASTER-Net observations report
  48. GRB 231210B: REM optical/NIR upper limits
  49. Fermi-LAT detection of increased gamma-ray activity of blazar PKS 2047+098, located inside the IceCube-231211A error region
  50. Fermi trigger No 724035412: Global MASTER-Net observations report
  51. GRB 231210B: MeerLICHT afterglow observations
  52. IceCube Alert 231211.03: Global MASTER-Net observations report
  53. IceCube-231202A: No candidates from the Zwicky Transient Facility
  54. GRB 231210B: detection of the optical counterpart with the LCOGT 40cm telescope at Sutherland Observatory
  55. Fermi trigger No 723906955: Global MASTER-Net observations report
  56. Swift GRB231210.90: Global MASTER-Net observations report
  57. GRB231205B: Swift/UVOT Upper Limits
  58. GRB 231205B: 1.3m DFOT Optical upper limit
  59. GRB 231205B: optical upper limit in TSHAOand AbAO
  60. Fermi trigger No 723581802: Global MASTER-Net observations report
  61. Fermi-LAT gamma-ray observations of IceCube-231202A
  62. GRB 231205B: REM optical/NIR upper limits
  63. GRB 231205B: NUTTelA-TAO / BSTI Early Optical Limits
  64. GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  65. GRB 231205B: Zadko observatory - Gingin optical observations
  66. GRB 231205B: Gaoyazi/GOT optical upper limit
  67. GRB 231205B: Nanshan/HMT optical upper limit
  68. Swift GRB231205.70: Global MASTER-Net observations report
  69. Fermi trigger No 723435916: Global MASTER-Net observations report
  70. Fermi trigger No 723326169: Global MASTER-Net observations report
  71. Fermi trigger No 723412808: Global MASTER-Net observations report
  72. Fermi trigger No 723279695: Global MASTER-Net observations report
  73. GRB 231129C: Swift-XRT afterglow detection
  74. Fermi trigger No 723149952: Global MASTER-Net observations report
  75. GRB 231129B: Swift-XRT observations
  76. Optical transient in the field of Messier 31, likely a new blazar: back to bright state
  77. GRB 231129C: MASTER OT detection
  78. GRB 231129A: JinShan optical upper limit
  79. GRB 231129C: Swift-XRT observations
  80. GRB 231129A: Swift/UVOT Upper Limits
  81. GRB 231129C: Tiled Swift observations
  82. Fermi trigger No 722977823: Global MASTER-Net observations report
  83. GRB 231129B: Tiled Swift observations
  84. Fermi-LAT gamma-ray observations of IceCube-231125A
  85. Integral GRB231129.21: Global MASTER-Net observations report
  86. GRB 231117A: MeerKAT 1.3GHz detection
  87. Fermi trigger No 722653947: Global MASTER-Net observations report
  88. GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
  89. Fermi trigger No 722460326: Global MASTER-Net observations report
  90. Fermi trigger No 722507896: Global MASTER-Net observations report
  91. Fermi trigger No 722462310: Global MASTER-Net observations report
  92. GRB 231115A: XMM-Newton observation
  93. GRB 231117A: Mondy optical observations
  94. Fermi trigger No 722400249: Global MASTER-Net observations report
  95. GRB 231118A: REM optical afterglow detection
  96. GRB 231117A: Chandra afterglow detection
  97. GRB 231117A: Continued GTC Observations
  98. Fermi trigger No 722349867: Global MASTER-Net observations report
  99. GRB 231118A: ATCA detection of radio counterpart
  100. GRB 231117A: Swift/UVOT late time observations

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