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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"

21095 results found.

  1. GRB 240101B: Swift/UVOT Upper Limits
  2. GRB 240101A: Swift/UVOT Upper Limits
  3. Swift GRB240101.85: Global MASTER-Net observations report
  4. Fermi trigger No 725806648: Global MASTER-Net observations report
  5. GRB 231230A: GOTO optical upper limits
  6. GRB 231230A: Swift/UVOT Upper Limits
  7. GRB 231230A: NOT optical upper limits
  8. Fermi trigger No 725592555: Global MASTER-Net observations report
  9. Swift GRB231230.06: Global MASTER-Net observations report
  10. Fermi trigger No 725143760: Global MASTER-Net observations report
  11. GRB 231222B: Swift-XRT afterglow detection
  12. Fermi trigger No 724921799: Global MASTER-Net observations report
  13. LAT GRB231222.31: Global MASTER-Net observations report
  14. GRB 231222A: Tiled Swift observations
  15. IceCube-231211A: GRANDMA observations of PKS2047+098
  16. GRB 231220A: Swift-XRT follow-up observations
  17. GRB 231220A: Swift ToO observations
  18. GRB 231220A: Swift/BAT-GUANO arcminute localization of a long burst
  19. Fermi trigger No 724781422: Global MASTER-Net observations report
  20. GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
  21. Fermi trigger No 724698747: Global MASTER-Net observations report
  22. GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
  23. GRB 231216A: optical upper limits from the INAF Asiago Observatory
  24. GRB 231215A: AMI-LA radio detection
  25. GRB 231216A: Nanshan/HMT optical upper limit
  26. GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
  27. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  28. GRB 231216A: REM NIR upper limits
  29. GRB 231216A: Swift/UVOT Upper Limits
  30. GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
  31. GRB 231216A: GIT optical upper limit
  32. GRB 231216A: NOT optical upper limits
  33. Swift GRB231216.77: Global MASTER-Net observations report
  34. GRB 231215A: optical afterglow detection from the INAF Asiago Observatory
  35. GRB 231215A: NOT optical observations
  36. GRB 231214A: Swift/UVOT Upper Limits
  37. GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
  38. GRB 231215A : OHP/T193 optical afterglow detection
  39. GRB 231215A: Swift/UVOT Detection
  40. ATCA observations of GRB 231210B
  41. Fermi trigger No 724326442: Global MASTER-Net observations report
  42. GRB 231214A: REM optical/NIR upper limits
  43. GRB 231215A : Nanshan/HMT optical observations
  44. GRB 231215C: MASTER OT detection
  45. Swift GRB231215.41: Global MASTER-Net observations report
  46. GRB 231215A: Swift-XRT observations
  47. Fermi trigger No 724278269: Global MASTER-Net observations report
  48. Fermi trigger No 724233240: Global MASTER-Net observations report
  49. Swift GRB231214.85: Global MASTER-Net observations report
  50. GRB 231210B: REM optical/NIR upper limits
  51. Fermi-LAT detection of increased gamma-ray activity of blazar PKS 2047+098, located inside the IceCube-231211A error region
  52. Fermi trigger No 724035412: Global MASTER-Net observations report
  53. GRB 231210B: MeerLICHT afterglow observations
  54. IceCube Alert 231211.03: Global MASTER-Net observations report
  55. IceCube-231202A: No candidates from the Zwicky Transient Facility
  56. GRB 231210B: detection of the optical counterpart with the LCOGT 40cm telescope at Sutherland Observatory
  57. Fermi trigger No 723906955: Global MASTER-Net observations report
  58. Swift GRB231210.90: Global MASTER-Net observations report
  59. GRB231205B: Swift/UVOT Upper Limits
  60. GRB 231205B: 1.3m DFOT Optical upper limit
  61. GRB 231205B: optical upper limit in TSHAOand AbAO
  62. Fermi trigger No 723581802: Global MASTER-Net observations report
  63. Fermi-LAT gamma-ray observations of IceCube-231202A
  64. GRB 231205B: REM optical/NIR upper limits
  65. GRB 231205B: NUTTelA-TAO / BSTI Early Optical Limits
  66. GRB 231205B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  67. GRB 231205B: Zadko observatory - Gingin optical observations
  68. GRB 231205B: Gaoyazi/GOT optical upper limit
  69. GRB 231205B: Nanshan/HMT optical upper limit
  70. Swift GRB231205.70: Global MASTER-Net observations report
  71. Fermi trigger No 723435916: Global MASTER-Net observations report
  72. Fermi trigger No 723326169: Global MASTER-Net observations report
  73. Fermi trigger No 723412808: Global MASTER-Net observations report
  74. Fermi trigger No 723279695: Global MASTER-Net observations report
  75. GRB 231129C: Swift-XRT afterglow detection
  76. Fermi trigger No 723149952: Global MASTER-Net observations report
  77. GRB 231129B: Swift-XRT observations
  78. Optical transient in the field of Messier 31, likely a new blazar: back to bright state
  79. GRB 231129C: MASTER OT detection
  80. GRB 231129A: JinShan optical upper limit
  81. GRB 231129C: Swift-XRT observations
  82. GRB 231129A: Swift/UVOT Upper Limits
  83. GRB 231129C: Tiled Swift observations
  84. Fermi trigger No 722977823: Global MASTER-Net observations report
  85. GRB 231129B: Tiled Swift observations
  86. Fermi-LAT gamma-ray observations of IceCube-231125A
  87. Integral GRB231129.21: Global MASTER-Net observations report
  88. GRB 231117A: MeerKAT 1.3GHz detection
  89. Fermi trigger No 722653947: Global MASTER-Net observations report
  90. GRB 231111A: Optical follow-up observations at Terskol, AbAO, Maidanak, Mondy, Assy
  91. Fermi trigger No 722460326: Global MASTER-Net observations report
  92. Fermi trigger No 722507896: Global MASTER-Net observations report
  93. Fermi trigger No 722462310: Global MASTER-Net observations report
  94. GRB 231115A: XMM-Newton observation
  95. GRB 231117A: Mondy optical observations
  96. Fermi trigger No 722400249: Global MASTER-Net observations report
  97. GRB 231118A: REM optical afterglow detection
  98. GRB 231117A: Chandra afterglow detection
  99. GRB 231117A: Continued GTC Observations
  100. Fermi trigger No 722349867: Global MASTER-Net observations report

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