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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"

10364 results found.

  1. Konus-Wind detection of GRB 250215A / EP250215a
  2. GRB 250217C: COLIBRÍ/DDRAGO Upper Limits on the Optical Counterpart
  3. GRB 250217C: SVOM/GRM observation
  4. SVOM/sb25021804: SVOM detection of a long X-ray transient
  5. GRB 250213A: Swift-XRT observations
  6. GRB 250216A: AstroSat CZTI detection
  7. GRB 250217C: AstroSat CZTI detection of a short burst
  8. Fermi GRB 250217A: Global MASTER-Net observations report
  9. GRB 250216A: Fermi GBM Final Real-time Localization
  10. GRB 250215A: Swift-XRT refined Analysis
  11. EP250215a / GRB 250215A: AstroSat CZTI detection
  12. EP250215a: Global MASTER-Net observations report
  13. EP250215a: EP-WXT detection and FXT follow-up observation of an X-ray transient
  14. Fermi GRB 250215A: Global MASTER-Net observations report
  15. Fermi trigger No 761206993: Global MASTER-Net observations report
  16. EP250212a: Liverpool Telescope optical upper limits
  17. EP250212a: EP-WXT detection and FXT follow-up observation of a fast X-ray transient
  18. Fermi GRB 250212A: Global MASTER-Net observations report
  19. Fermi trigger No 760945500: Global MASTER-Net observations report
  20. GRB 250211B: A long GRB detected by INTEGRAL
  21. LIGO/Virgo/KAGRA S250206dm: GECKO Continued Observaiton with 7DT
  22. GRB 250207A: Fermi GBM Observation
  23. Konus-Wind detection of GRB 250207A
  24. Konus-Wind detection of GRB 250206A
  25. EP250207b: Global MASTER-Net observations report
  26. GRB 250207A: Skynet optical afterglow observations
  27. GRB 250210A: AstroSat CZTI detection
  28. EP250207b: a new X-ray transient detected by Einstein Probe
  29. GRB 250209A: MAXI/GSC detection (possible detection of an X-ray flare from 1RXS J145110.3+310648)
  30. Fermi GRB 250210A: Global MASTER-Net observations report
  31. LIGO/Virgo/KAGRA S250206dm: Global MASTER-Net observations report
  32. IceCube Alert 250207.09: Global MASTER-Net observations report
  33. Fermi-LAT Gamma-ray Observations of IceCube-250207A
  34. LIGO/Virgo/KAGRA S250207bg: Updated NED Galaxies in the Localization Volume
  35. LIGO/Virgo/KAGRA S250206dm: GECKO Observation with 7DT and KMTNet
  36. LIGO/Virgo/KAGRA S250206dm: (Update-7) NED Galaxies in the Localization Volume
  37. GRB 250206A: Fermi-LAT detection
  38. LIGO/Virgo/KAGRA S250206dm: COLIBRÍ/DDRAGO Observations of the DDOTI optical candidates
  39. GRB 250207A: Swift-XRT refined Analysis
  40. LIGO/Virgo/KAGRA S250207bg: NED Galaxies in the Localization Volume
  41. Konus-Wind detection of GRB 250204B
  42. GRB 250129A: Continued AbAO and Mondy optical observations
  43. GRB 250207B: MAXI/GSC detection
  44. The EP-WXT trigger 01709131332 is likely a flaring star
  45. LIGO/Virgo/KAGRA S250206dm: Updated-6 NED Galaxies in the Localization Volume
  46. Fermi-LAT Gamma-ray Observations of IceCube-250203A
  47. LIGO/Virgo/KAGRA S250206dm: Coverage and upper limits from MAXI/GSC observations
  48. LIGO/Virgo/KAGRA S250206dm: Updated NED Galaxies in the Localization Volume
  49. LIGO/Virgo/KAGRA S250206dm: NED Galaxies in the Localization Volume
  50. EP250205a/GRB 250205A: Einstein Probe observation
  51. LIGO/Virgo/KAGRA S250205bk: NED Galaxies in the Localization Volume
  52. Konus-Wind detection of GRB 250201A
  53. Konus-Wind detection of GRB 250202B
  54. GRB 250204B: AstroSat CZTI detection of a short burst
  55. GRB 250202C: GRBAlpha detection
  56. GRB 250129A: 7DT Detection and Medium-band SED of Afterglow
  57. GRB 250202C: Fermi GBM Final Real-time Localization
  58. GRB 250202B: AstroSat CZTI detection of a bright long GRB
  59. Swift GRB250129A: MASTER 4 days observations report
  60. GRB 250201A: INTEGRAL SPI/ACS detection
  61. Konus-Wind detection of GRB 250129A
  62. LIGO/Virgo/KAGRA S250201i: Coverage and upper limits from MAXI/GSC observations
  63. EP250108A / SN 2025kg: Upper limits from a neutrino search with IceCube
  64. GRB 250128B: VLA possible radio detection
  65. GRB 250127A: EP-FXT second observation epoch and confirmation of the x-ray afterglow fading
  66. GRB 250129A: Skynet optical observations
  67. GRB 250129A: Swift-XRT refined Analysis
  68. The EP-WXT trigger 01709131085: KAIT confirmation of the stellar flare
  69. GRB 250128B: VLT/FORS2 optical observations
  70. GRB 250128B: Swift-XRT refined Analysis
  71. Swift GRB 250128B: Global MASTER-Net observations report
  72. EP250125a: Upper limits from Swift/BAT-GUANO
  73. GRB 250128B: Swift detection of a short burst
  74. GRB 250127B: DDOTI Upper Limit on the Afterglow
  75. Fermi-LAT Gamma-ray Observations of IceCube-250102A
  76. GRB 250127A: EP-FXT afterglow detection
  77. GRB 250117A: Fermi GBM Observation
  78. Fermi GRB 250127B: Global MASTER-Net observations report
  79. Fermi-LAT Gamma-ray Observations of IceCube-250101A
  80. GRB 250126A: MAXI/GSC detection
  81. EP250108a / SN 2025kg: Refined Analysis of EP-WXT Detection
  82. EP250125a: a new X-ray transient detected by Einstein Probe
  83. Konus-Wind detection of a bright burst from SGR 1E1841-045 on 2025 January 23
  84. GRB 250121A: Swift/BAT-GUANO localization skymap of a burst
  85. IPN triangulation of a bright burst from SGR 1E1841-045
  86. EP250108a: AbAO, CMO and Terskol optical upper limits
  87. Konus-Wind detection of GRB 250118B
  88. GRB 250121A: Fermi GBM Observation
  89. IPN triangulation of GRB 250118B
  90. Konus-Wind detection of GRB 250119B
  91. IPN triangulation of GRB 250119B
  92. GRB 250121A: Fermi-LAT detection
  93. LIGO/Virgo S250119cv: Swift XRT observations, 5 X-ray sources
  94. GRB 250119C: Swift/BAT-GUANO localization skymap of a short burst
  95. GRB 250119B: Swift/BAT-GUANO localization skymap of a long burst
  96. Fermi-LAT Gamma-ray Observations of IceCube-241224A
  97. GRB 250118A: Swift/BAT-GUANO localization skymap of a short burst
  98. Konus-Wind detection of GRB 250117A
  99. IPN triangulation of GRB 250117A (short)
  100. LIGO/Virgo/KAGRA S250119cv: Updated NED Galaxies in the Localization Volume

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