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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"

28221 results found.

  1. GRB 240916B: Fermi GBM Final Real-time Localization
  2. GRB 240914B: Fermi GBM Final Localization
  3. GRB 240916A: Fermi GBM Final Real-time Localization
  4. EP240913a/GRB 240913C: KAIT optical upper limit
  5. GRB 240913C: Fermi GBM detection
  6. GRB 240914A: Swift-XRT observations
  7. GRB 240914B: AstroSat CZTI detection
  8. EP240913A / GRB 240913C: AstroSat CZTI detection
  9. GRB 240910A: SVOM/VT optical observations
  10. GRB 240914A: Swift ToO observations
  11. EP240913a: ESO-NTT optical observations
  12. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  13. GRB 240905E: further NOT optical observations
  14. EP240913a: EP-WXT detection of a fast X-ray transient
  15. GRB 240913B: Fermi GBM Final Real-time Localization
  16. GRB 240911A: LCO optical observations
  17. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  18. GRB 240912A: Swift/UVOT Detection
  19. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  20. GRB 240911A: Swift-XRT observations
  21. GRB 240913A: Fermi GBM Final Real-time Localization
  22. GRB 240912A: J-band observations with WINTER
  23. GRB 240912A: Swift-XRT refined Analysis
  24. GRB 240912A: Fermi GBM Observation
  25. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  26. GRB 240911A: Tiled Swift observations
  27. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE
  28. GRB 240912B: Fermi GBM Final Real-time Localization
  29. GRB 240912A: NOT optical spectroscopy
  30. GRB 240912A: Enhanced Swift-XRT position
  31. GRB 240912A: Redshift from OSIRIS+/GTC
  32. GRB 240910A: Redshift from OSIRIS+/GTC
  33. GRB 240912A: Swift detection of a burst with an optical counterpart
  34. GRB 240912A: Fermi GBM Final Real-time Localization
  35. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  36. GRB 240910A: JinShan optical observations
  37. GRB 240910A: GOTO candidate optical counterpart
  38. EP240908a: Optical afterglow confirmation
  39. GRB 240910A: Swift ToO observations
  40. IPN triangulation of GRB 240905B (short)
  41. GRB 240825A: 7DT Optical Upper Limit
  42. GRB 240905E: SVOM/VT optical observations
  43. GRB 240910A: GRBAlpha detection
  44. GRB 240910B: Fermi GBM Final Real-time Localization
  45. EP240908a: Updates on the WXT detection result around the trigger time
  46. GRB 240910A: Fermi GBM Final Real-time Localization
  47. EP240908a: optical afterglow candidate
  48. GRB 240905B: GOTO optical upper limits
  49. EP240908a: EP detection of a fast X-ray transient
  50. GRB 240908A: Fermi GBM Final Real-time Localization
  51. GRB 240905E: GIT optical upper limit
  52. GRB 240905B: Swift-XRT observations
  53. GRB 240905E: Gaoyazi/GOT optical upper limits
  54. GRB 240905B: Fermi-LAT detection
  55. GRB 240905B: Swift ToO observations
  56. GRB 240905E: J-band observations with WINTER
  57. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  58. GRB 240905E: AKO Optical Upper Limit
  59. GRB 240905E: SVOM/C-GFT optical upper limit
  60. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  61. GRB 240905E: NOT optical upper limits
  62. GRB 240905E: REM optical/NIR upper limits
  63. GRB 240902B: AstroSat CZTI detection of a long burst
  64. GRB 240905E: Swift-XRT refined Analysis
  65. GRB 240902A: AstroSat CZTI detection of a long burst
  66. GRB 240905E: LCOGT Optical Upper Limit
  67. GRB 240905E: Swift/UVOT Upper Limits
  68. GRB 240905E: SAO RAS optical upper limit
  69. GRB 240825A: Montarrenti Observatory optical follow-up observations
  70. GRB 240905E: Nanshan/HMT optical upper limit
  71. GRB 240905E: Swift detection of a burst
  72. GRB 240819A: Optical upper limits from TESS
  73. GRB 240905D: AstroSat CZTI detection
  74. GRB 240905D: Fermi GBM Final Real-time Localization
  75. GRB 240905B: AstroSat CZTI detection and localization
  76. GRB 240905C: Fermi GBM Final Real-time Localization
  77. GRB 240905B: Fermi GBM Final Real-time Localization
  78. GRB 240825A: ATCA Detection of Radio Counterpart
  79. GRB 240905A: Fermi GBM Final Real-time Localization
  80. GRB 240904A: Swift detection of a burst
  81. GRB 240828A: GECAM detection
  82. GRB 240831B: Fermi GBM Final Localization
  83. GRB 240825A: Magnitude Correction in SVOM/C-GFT Optical Observations
  84. GRB 240825A: MeerLICHT afterglow detection
  85. GRB 240821A: VLT spectroscopic observations
  86. GRB 240825A: TSHAO Optical Upper Limit
  87. GRB 240829B: GRBAlpha detection
  88. GRB240828B: REM optical/NIR upper limits
  89. GRB 240828B: AbAO optical upper limit
  90. GRB 240831A: Fermi GBM Final Real-time Localization
  91. GRB 240828B: Mephisto optical upper limit
  92. GRB 240828B: GRANDMA Optical Upper Limit
  93. GRB 240825A: MeerKAT detection
  94. GRB 240828B: J-band upper limit from WINTER
  95. GRB 240828B: GMG Optical Upper Limit
  96. GRB 240828A: KAIT continued optical observations
  97. GRB 240828B: GWAC-F50A optical upper limit
  98. GRB 240828B: SVOM/C-GFT optical upper limit
  99. GRB 240828B: SAO RAS optical upper limit
  100. GRB 240828B: KAIT optical upper limit

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