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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"

21526 results found.

  1. GRB 230307A: ASO-S/HXI detection
  2. GRB 230228A: NUTTelA-TAO / BSTI Optical Limits
  3. GRB 230307A: optical upper limit
  4. GRB 230217A: ATCA rapid-response radio detection
  5. Swift Trigger 1159108 is not a GRB
  6. GRB 230307A: Swift/BAT upper limits on the early afterglow
  7. GRB 230307A: Swift-XRT observations
  8. GRB 230228A: VIRT Optical Upper Limit
  9. Improved IPN localization for GRB 230307A
  10. GRB 230307A: Tiled Swift observations
  11. IPN triangulation of GRB 230307A (long/very bright)
  12. GRB 230228A: 6 GHz VLA radio upper limit
  13. GRB 230228A: Swift-BAT refined analysis
  14. GRB 230228A: Swift/UVOT Upper Limits
  15. GRB 230228A: Fermi GBM Observation
  16. GRB 230228A: OSN optical upper limit
  17. GRB 230228A: Swift-XRT refined Analysis
  18. GRB 230228A: Mondy optical upper limit
  19. GRB 230228A: Enhanced Swift-XRT position
  20. GRB 230228A: Nanshan/NEXT optical upper limit
  21. GRB 230228A: Miryang Arirang Astronomical Observatory (MAAO) 0.7-m telescope optical upper limit
  22. GRB 230228A: Prompt enhanced Swift-XRT position
  23. GRB 230228A: Swift detection of a possibly short burst
  24. GRB 230217A: VLT/FORS2 optical observations and candidate counterpart
  25. GRB 230216A Mondy Observations
  26. GRB 230217A: Swift/UVOT Upper Limits
  27. GRB 230216A: Swift/UVOT Upper Limits
  28. GRB 230217A: Continued Gemini Observations
  29. GRB 230217A: Swift-XRT afterglow detection
  30. GRB 230217A: Swift-BAT refined analysis
  31. GRB 230217A: AstroSat CZTI detection
  32. GRB 230217A: 6 GHz VLA observations
  33. GRB 230217A: Fermi GBM observation
  34. Konus-Wind detection of GRB 230217A
  35. GRB 230217A: Swift-XRT observations
  36. GRB 230217A: AGILE/MCAL detection
  37. GRB 230207B: CALET Gamma-Ray Burst Monitor detection
  38. GRB 230216A: SVOM/C-GFT optical upper limit
  39. GRB 230217A: Swift detection of a short burst
  40. GRB 230216A: Swift-BAT refined analysis
  41. GRB 230216A: Swift-XRT refined Analysis
  42. GRB 230205A: Lowell Discovery Telescope Observations
  43. Swift GRB 230216A: Global MASTER-Net observations report
  44. GRB 230216A: Enhanced Swift-XRT position
  45. GRB 230216A: AKO Upper Limit
  46. GRB 230216A: Zadko observatory - Gingin optical observations
  47. GRB 230216A: Swift detection of a burst
  48. GRB 230209B: AGILE detection
  49. GRB 230209B: Fermi GBM Observation
  50. IPN triangulation of GRB 230209B
  51. GRB 230204B: CALET Gamma-Ray Burst Monitor detection
  52. GRB 230209B: Swift/BAT-GUANO detection outside the coded FOV
  53. Swift Trigger 1153670 is probably not a GRB
  54. GRB 230205A: 6 GHz VLA observations
  55. GRB 230205A: SUBARU HSC pre-imaging for host galaxy search
  56. GRB 221009A: Continued Swift Observations
  57. GRB 230207B: Detection by GRBAlpha
  58. GRB 230205A: possible host galaxy detection with the Schmidt - Asiago telescope
  59. GRB 230207B: Swift/BAT-GUANO detection outside the coded FOV
  60. ZTF23aabmzlp/AT2023azs: Neil Gehrels Swift Observatory X-ray observations
  61. GRB 230204B: Swift/UVOT Upper Limits
  62. GRB 230205A: Swift/UVOT Upper Limits
  63. GRB 230204B: Fermi GBM detection
  64. GRB 230205A: LCOGT Optical Upper Limits
  65. GRB 230204B: Swift-XRT afterglow detection
  66. GRB 230205A: SVOM/C-GFT optical upper limit
  67. GRB 230205A: Swift-BAT refined analysis (T90 = 2.3 s)
  68. GRB 230204A: Swift-BAT refined analysis
  69. GRB 230205A: Swift-XRT refined Analysis
  70. GRB 230204B: Swift ToO observations
  71. GRB 230205A: Enhanced Swift-XRT position
  72. GRB 230205A: BOOTES-5/JGT early optical upper limit
  73. GRB 230204B: Detection by GRBAlpha
  74. GRB 230204B: AGILE detection
  75. GRB 230205A: Swift detection of a burst
  76. GRB 230204B: GIT discovery of the likely optical afterglow
  77. GRB 230204B: AstroSat CZTI detection
  78. GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
  79. GRB 230204A: Swift/UVOT Upper Limits
  80. GRB 230204A: Swift-XRT refined Analysis
  81. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  82. GRB 230204A: Enhanced Swift-XRT position
  83. GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
  84. GRB 221216A: Swift-BAT refined analysis
  85. AT2023avj: X-ray Detection with Swift/XRT
  86. Swift-XRT observations of NuEm-230125A
  87. Trigger 1150965: Swift detection of LS V +44 17
  88. GRB 230124A: Fermi GBM Observation
  89. GRB 230124A: Swift/BAT-GUANO detection outside the coded FOV
  90. GRB 230123A: LCOGT Optical Upper Limits
  91. GRB 230123A: Swift-BAT refined analysis
  92. GRB 230122A: Swift/BAT-GUANO detection
  93. GRB 230123A: Swift/UVOT Upper Limits
  94. GRB 230123A: Swift-XRT refined Analysis
  95. GRB 230123A: Enhanced Swift-XRT position
  96. GRB 230123A: Zadko observatory - Gingin optical observations
  97. GRB 230116C: Swift-XRT observations
  98. GRB 230123A: Swift detection of a burst
  99. Trigger 1150107: Swift detection of LS V +44 17
  100. GRB 230116D: 3.6m DOT optical upper limit

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