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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.

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

11552 results found.

  1. Konus-Wind detection of GRB 250920A
  2. IPN triangulation of GRB 250920A (long/bright)
  3. GRB 250916A: Swift/UVOT Detection
  4. GRB 250920B: Glowbug gamma-ray detection
  5. GRB 250916A: CrAO ZTSh R-band optical observations
  6. GRB 250916A: SAO RAS Zeiss-1000 optical observations
  7. GRB 250922A: Fermi GBM Final Localization
  8. GRB 250920B: Kitab-ISON optical upper limit
  9. GRB 250917B: Mondy and Zeiss-1000 SAO RAS optical observations, optical observations, afterglow candidate
  10. GRB 250920C: SVOM/GRM observation
  11. GRB 250920C: GTC/OSIRIS+ spectroscopic redshift z = 1.40
  12. GRB 250917B: KAIT optical upper limit
  13. GRB 250920A: NuSTAR detection of bright prompt emission
  14. GRB 250920C: GROWTH-India Telescope optical observations
  15. GRB 250916A: FTW optical and NIR observations of the counterpart
  16. GRB 250920B: Fermi GBM Observation
  17. GRB 250920A: Fermi GBM Detection
  18. GRB 250920C: Fermi GBM Observation
  19. GRB 250920B: FTW optical and NIR observations of the counterpart
  20. GRB 250920A: SVOM/GRM observation
  21. GRB 250920B: SVOM/C-GFT optical observations
  22. GRB 250920C: GOTO optical counterpart candidate
  23. GRB 250919A / EP250919a: LCO optical observation
  24. Konus-Wind detection of GRB 250919A
  25. GRB 250920C: Fermi GBM Final Real-time Localization
  26. GRB 250919A / EP250919a: Insight-HXMT detection
  27. GRB 250920A: AstroSat CZTI detection
  28. GRB 250920B: Fermi GBM Final Real-time Localization
  29. GRB 250920A: BALROG localization (Fermi Trigger 780029651 / GRB 250920121)
  30. GRB 250920A: Fermi GBM Final Localization
  31. GRB 250919A/EP250919a: SVOM/VT optical observation
  32. GRB 250919A / EP250919a: MASTER bright afterglow detection 24h after GRB time
  33. GRB 250916A: Mondy R-band optical observations
  34. GRB 250919A: Glowbug gamma-ray detection
  35. GRB 250919A: Fermi GBM Observation
  36. Fermi GRB 250918A: Global MASTER-Net observations report
  37. GRB 250919A / EP250919a: NuSTAR detection of bright prompt emission
  38. GRB 250918A: SVOM/GRM observation
  39. GRB 250919A/EP250919A: Swift/UVOT afterglow detection
  40. GRB 250919A: Swift-XRT afterglow detection
  41. GRB 250919A: Fermi-LAT detection
  42. EP250919a/GRB 250919A: Gemini/GMOS-S spectroscopic redshift z = 1.145
  43. GRB 250919A: SVOM/GRM observation of a very bright GRB
  44. GRB 250919A: BALROG localization (Fermi Trigger 779934537 / GRB 250919020)
  45. GRB 250916A: Fermi GBM Observation
  46. Fermi GRB 250919A: Global MASTER-Net observations report
  47. GRB 250919A: Fermi GBM Final Real-time Localization
  48. GRB 250916A: KAIT optical observations
  49. GRB 250917B: VLT/HAWK-I near-infrared observations
  50. GRB 250916A: NuSTAR detection of the prompt emission
  51. GRB 250916A: further SAO RAS optical observations
  52. GRB 250912A: SVOM/ECLAIRs refined analysis
  53. GRB 250918A: BALROG localization (Fermi Trigger 779891543 / GRB 250918522)
  54. GRB 250918A: Fermi GBM Final Real-time Localization
  55. GRB 250917B: Swift/UVOT Upper Limits
  56. GRB 250916A: OSIRIS+/GTC redshift z = 2.015
  57. GRB 250916A: Swift-XRT observations
  58. GRB 250916A: MAO/AZT-22 optical observations
  59. GRB 250916A: SAO RAS optical observations
  60. GRB 250916A : GIT optical observations
  61. GRB 250916A: Glowbug gamma-ray detection
  62. GRB250917B: WFST optical observations
  63. GRB 250916A: Swift ToO observations
  64. GRB 250917B: Fermi GBM Observation
  65. Fermi GRB 250917B: Global MASTER-Net observations report
  66. GRB 250916A: GOTO optical counterpart candidate
  67. GRB 250917B: Fermi GBM Final Real-time Localization
  68. GRB 250917A: Fermi GBM Final Real-time Localization
  69. GRB 250916A: AstroSat CZTI detection of a bright long burst
  70. Fermi GRB 250916A: Global MASTER-Net observations report
  71. GRB 250916A: Fermi GBM Final Real-time Localization
  72. GRB 250912A: Swift/BAT-GUANO localization skymap of a possibly short burst
  73. GRB 250912A: SVOM/COLIBRÍ (FM-GFT) optical observations
  74. GRB 250912A: Swift-XRT observations
  75. GRB250912A: VLT/HAWK-I follow-up observations
  76. GRB 250912A: Fermi GBM Observation
  77. GRB 250912A: SVOM/GRM analysis suggests a possible short GRB with extended emission
  78. GRB 250912A: LCO optical upper limit
  79. Fermi GRB 250912A: Global MASTER-Net observations report
  80. GRB 250912A: SVOM detection of a burst
  81. GRB 250912A: Fermi GBM Final Real-time Localization
  82. EP250911a: Upper limit from Fermi-GBM Observations
  83. GRB 250910B: SVOM/GRM observation
  84. GRB 250910C: Fermi GBM Final Localization Correction
  85. Fermi GRB 250910B: Global MASTER-Net observations report
  86. GRB 250910B: BALROG localization (Fermi Trigger 779223130 / GRB 250910786)
  87. GRB 250910B: Fermi GBM Final Real-time Localization
  88. GRB 250909A: AstroSat CZTI detection
  89. GRB 250702B: Late time Chandra observations
  90. Fermi GRB 250909A: Global MASTER-Net observations report
  91. GRB 250909A: Fermi GBM Final Real-time Localization
  92. Fermi-LAT Gamma-ray Observations of IceCube-250905A
  93. IceCube-250905A - IceCube observation of a high-energy neutrino candidate track-like event
  94. GRB 250905B: Fermi GBM Final Localization
  95. EP250827a and EP250827b: Upper limit from Fermi-GBM Observations
  96. GRB 250902B: CALET Gamma-Ray Burst Monitor detection
  97. GRB 250902A: CALET Gamma-Ray Burst Monitor detection
  98. GRB 250902A: VZLUSAT-2 detection
  99. GRB 250902A: GECAM-B detection
  100. GRB 250902B: AstroSat CZTI detection

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