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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

850 results found.

  1. GRB 231129C: MASTER OT detection
  2. GRB 231129C: Fermi-LAT detection
  3. GRB 231129C: GRBAlpha detection
  4. GRB 231129C: Glowbug gamma-ray detection
  5. GRB 231129C: GECAM-B detection of a bright burst
  6. GRB 231129C: AstroSat CZTI detection
  7. GRB 231129C: CALET Gamma-Ray Burst Monitor detection
  8. GRB 231129C: Fermi GBM Observation of a very bright GRB
  9. GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
  10. GRB 231129C: MAXI/GSC detection
  11. GRB 231129B: Tiled Swift observations
  12. GRB 231129B: MAXI/GSC detection
  13. Fermi trigger No 722460326: Global MASTER-Net observations report
  14. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  15. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  16. LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
  17. LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
  18. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  19. GRB 231004A: Glowbug gamma-ray detection
  20. LIGO/Virgo/KAGRA S230927be: Updated Sky localization
  21. LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
  22. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  23. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  24. LIGO/Virgo/KAGRA S230917af: MAXI/GSC observations
  25. Trigger 1187142: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  26. MAXI/GSC detection of Swift J1727.8-1613 (GRB 230824A)
  27. LIGO/Virgo/KAGRA S230802aq: Coverage and upper limits from MAXI/GSC observations
  28. LIGO/Virgo/KAGRA S230731an: Coverage and upper limits from MAXI/GSC observations
  29. IceCube Alert 230724.08: Global MASTER-Net observations report
  30. IceCube-230707A : MAXI upper limit and NICER follow-up observation of Swift J1753.5-0127
  31. Konus-Wind detection of GRB 220623A
  32. LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
  33. GRB 230623A: Swift-XRT observations
  34. GRB 230623A: Tiled Swift observations
  35. MAXI GRB 230623A: MASTER optical observations
  36. GRB 230623A: Tiled Swift observations
  37. GRB 230623A: MAXI/GSC detection
  38. LIGO/Virgo/KAGRA S230529ay: Coverage and upper limits from MAXI/GSC observations
  39. GRB 230520A: CALET Gamma-Ray Burst Monitor detection
  40. GRB 230520A: MAXI/GSC detection
  41. LIGO/Virgo/KAGRA S230518h: Coverage and upper limits from MAXI/GSC observations
  42. GRB 230510B: Fermi GBM detection
  43. GRB 230510B: AstroSat CZTI detection
  44. GRB 230510B: CALET Gamma-Ray Burst Monitor detection
  45. GRB 230510B: MAXI/GSC detection
  46. MAXI GRB230408.82: Global MASTER-Net observations report
  47. GRB 230307A: soft X-ray detection with LEIA
  48. GRB 230307A: MAXI/GSC upper limit
  49. GRB 230220A: Correction to GCN 33352
  50. GRB 230220A: MAXI/GSC detection
  51. GRB 230204B: CALET Gamma-Ray Burst Monitor detection
  52. GRB 230204B: ATCA radio detection
  53. Fermi GRB 230209B: Global MASTER-Net observations report
  54. GRB 230204B: MASTER early OT detection
  55. GRB 230204B: Swift/UVOT Upper Limits
  56. GRB 230204B: Fermi GBM detection
  57. GRB 230204B: Swift-XRT afterglow detection
  58. GRB 230204B: 3.6m DOT optical observation
  59. GRB 230204B: ATLAS detection of the optical afterglow and a projected location in a nearby galaxy group
  60. GRB 230204B: Swift ToO observations
  61. GRB 230204B: Detection by GRBAlpha
  62. GRB 230204B: AGILE detection
  63. GRB 230204B: GIT discovery of the likely optical afterglow
  64. GRB 230204B: AstroSat CZTI detection
  65. GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
  66. GRB 230204B: MAXI/GSC detection
  67. GRB 230111A: Fermi GBM Observation
  68. GRB 230111A: MAXI/GSC detection
  69. Fermi trigger No 694232203: Global MASTER-Net observations report
  70. GRB 221028B: MAXI/GSC detection
  71. Konus-Wind detection of GRB 221017A
  72. GRB 221017A: CALET Gamma-Ray Burst Monitor detection
  73. GRB 221017A: Swift-XRT observations
  74. GRB 221017A: Swift ToO observations
  75. IPN triangulation of GRB 221017A (long)
  76. MAXI GRB221017.24: Global MASTER-Net observations report
  77. GRB 221017A: MAXI/GSC detection
  78. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
  79. MAXI GRB 221006A: Redshifts of the possible host galaxies
  80. GRB 221006A: Swift-XRT afterglow detection
  81. Afterglow limits of GRB 221006A from OHP
  82. GRB 221009A: NICER follow-up observations
  83. GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
  84. GRB 221006A: Swift ToO observations
  85. GRB 221006A: CALET Gamma-Ray Burst Monitor detection
  86. GRB 221009A BOOTES-2/TELMA and OSN optical detections
  87. GRB 221008A: Swift-XRT observations
  88. GRB 221008A: Tiled Swift observations
  89. GRB 221008A: MAXI/GSC detection
  90. GRB 221006A: Swift-XRT observations
  91. GRB 221006A: Tiled Swift observations
  92. GRB 221006A: MAXI/GSC detection
  93. GRB 220907A: Swift/UVOT Upper Limits
  94. GRB 220706A: MAXI/GSC detection 84 minutes after the Swift Trigger
  95. MAXI GRB220706.73: Global MASTER-Net observations report
  96. Trigger 1113743: Swift detection of MAXI J0655-013
  97. Swift Detection of MAXI J0655-013
  98. GRB 220609B: AstroSat CZTI detection
  99. Fermi GRB 220608A: Global MASTER-Net observations report
  100. MAXI GRB220607.31: Global MASTER-Net observations report

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