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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').
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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"

15266 results found.

  1. EP251214b: KAIT optical upper limit
  2. GRB 251214B: 1.6m Mephisto observations with newly installed mosaic cameras
  3. GRB 251215A: Glowbug gamma-ray detection
  4. GRB 251214B: UAFO optical upper limit
  5. GRB 251213A: GRID-10B observation
  6. GRB 251214B: AbAO optical observations
  7. GRB 251209A: GECAM-B observation of a long burst
  8. GRB 251214D: GECAM-B observation of a long burst
  9. GRB 251214B: Fermi GBM Observation
  10. GRB 251209A: Insight-HXMT/HE detection
  11. GRB 251215A: Swift ToO observations
  12. GRID detection of GRB 251213A
  13. GRB 251203B: AbAO optical observations
  14. GRB 251215A: Swift/BAT-GUANO arcminute localization of a burst
  15. GRB 251214B: GECAM-B observation of a long burst
  16. GRB 251213A: SVOM/GRM observation
  17. EP251214a: KAIT optical upper limit
  18. GRB 251214D: AstroSat CZTI detection of a long burst
  19. GRB 251213A: AstroSat CZTI detection
  20. GRB 251214A: AstroSat CZTI detection
  21. GRB 251213A: GECAM-B detection
  22. GRB 251214A: GECAM-B observation of a likely long burst
  23. EP251214a: COLIBRÍ optical upper limit
  24. EP251214a: EP-WXT detection of an X-ray transient possibly associated with GRB 251214A
  25. EP251212a: KAIT optical upper limit
  26. EP251212a / GRB 251212A: AstroSat CZTI detection
  27. GRB 251211B: AstroSat CZTI detection
  28. IceCube-251210A: No Candidate Transients from the Zwicky Transient Facility
  29. Fermi-LAT Gamma-ray Observations of IceCube-251210A
  30. IceCube-251210A: Upper limits from a search for additional neutrino events in IceCube
  31. IceCube-251210A: DDOTI Optical Upper Limit
  32. GRB 251209A: Fermi GBM observation
  33. GRB 251209A: AstroSat CZTI detection
  34. IceCube-251210A - IceCube observation of a high-energy neutrino candidate track-like event
  35. EP251124a: Mondy optical upper limit
  36. GRB 251208A: AstroSat CZTI detection
  37. EP251118a / GRB 251118C: VLT/MUSE redshift confirmation
  38. GRB 251208C: GECAM-B observation of a short burst
  39. GRB 251208A: GECAM-B observation of a short burst
  40. GRB 251208D: LAST optical upper limit
  41. GRB 251208D: LCO analysis of the XRT sources
  42. GRB 251208B: Fermi GBM Observation
  43. GRB 251208A: SVOM/GRM observation of a short burst
  44. GRB 251208C: SVOM/GRM observation of a short burst
  45. GRB 251205A: Liverpool Telescope further optical follow-up observations
  46. GRB 251208B: Swift ToO observations
  47. GRB 251208B: Fermi-LAT detection
  48. GRB 251208B: Swift/BAT-GUANO arcminute localization of a burst
  49. GRB 251208D: SVOM possible detection of a faint burst
  50. GRB 251206A: SVOM detection of a burst through offline search
  51. GRB 251205A : MITSuME Akeno optical afterglow candidate detection
  52. GRB 251205A: FTW optical and NIR observations
  53. EP-WXT trigger 01709249380: KAIT confirmation of a stellar flare
  54. GRB 251205A: Liverpool Telescope further optical follow-up observations
  55. EP-WXT trigger 01709249380: confirmation of a stellar flare by BOOTES-5
  56. GRB 251205A: ZTF and ATLAS optical afterglow detections
  57. GRB 251205A: GROWTH-India Telescope optical observations
  58. GRB 251205A: Liverpool Telescope optical follow-up observations
  59. GRB 251203C: Swift/UVOT Upper Limit
  60. Konus-Wind detection of GRB 251118A
  61. GRB 251203A: Insight-HXMT/HE detection
  62. GRB 251203C: SVOM/ECLAIRs refined analysis
  63. SVOM/sb25120502: SVOM detection of a faint X-ray transient candidate
  64. GRB 251202A / EP251202a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm and 1-m telescopes at McDonald Observatory
  65. GRB 251203C: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  66. GRB 251202A: SVOM/GRM observation
  67. GRB 251203A: GECAM-B observation of a burst
  68. GRB 251203A: SVOM/GRM observation
  69. GRB 251203A: AstroSat CZTI detection
  70. EP251130a: JinShan near-infrared observations
  71. GRB 251203C: LCO optical afterglow confirmation
  72. GRB 251129A/EP251129a : SVOM/ECLAIRs refined analysis
  73. GRB 251129B: GECAM-B observation of a burst
  74. GRB 251203B: confirmation of a stellar flare by BOOTES-2
  75. GRB 251202A / EP251202a: Liverpool Telescope optical follow-up observations
  76. GRB 251203C: SVOM detection of a burst
  77. GRB 251203B: SVOM detection of a burst
  78. GRB 251201B: Insight-HXMT/HE detection
  79. EP251202a / GRB 251202A: Insight-HXMT/HE detection
  80. EP251130a: MAO/AZT-22 optical observations
  81. EP251202a / GRB251202A: AstroSat CZTI detection
  82. GRB 251201B: Fermi GBM Observation
  83. EP251130a: ULL-ASTRO-MASTER late detection of the optical afterglow with LCO 1-m telescope at Teide Observatory
  84. GRB 251129B: AstroSat CZTI detection
  85. GRB 251202A: Fermi GBM Observation
  86. GRB 251201B: Kilonova-Catcher optical afterglow detection
  87. GRB 251201B: GECAM-B observation of a long burst
  88. EP251130a: continued NOT optical observations indicate steep fading phase
  89. Fermi-LAT Gamma-ray Observations of IceCube-251130A
  90. GRB 251201A: GECAM-B observation of a burst
  91. GRB 251202A: Swift-XRT afterglow detection
  92. EP251129a/GRB 251129A: NOWT Detection
  93. EP251202a/GRB 251202A: Einstein Probe detection of an X-ray transient
  94. IceCube-251130A: Upper limits from a search for additional neutrino events in IceCube
  95. GRB 251201A: SVOM/GRM observation of a burst
  96. GRB 251130B: AstroSat CZTI detection
  97. EP251130a: SAO RAS optical observations
  98. EP251130a: refined analysis of the EP-WXT and EP-FXT observations
  99. EP251130a: JinShan optical observations
  100. GRB 251127A: SVOM/GRM observation

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