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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"

12169 results found.

  1. Fermi GRB 250309A: Global MASTER-Net observations report
  2. Fermi-LAT gamma-ray observations of IceCube-250309A
  3. IceCube Alert 250309.32: Global MASTER-Net observations report
  4. EP250308a: Einstein Probe detection of an X-ray transient
  5. The EP-WXT trigger 01709132387 is likely a flaring star
  6. Fermi GRB 250307A: Global MASTER-Net observations report
  7. Konus-Wind detection of GRB 250306A
  8. IceCube-241016A: MASTER flaring blazar 5BZU J073038.29-320820.2 with Zhirkov effect
  9. GRB 250305A: AstroSat CZTI detection
  10. GRB 250306A: AstroSat CZTI detection
  11. Fermi trigger No 762963055: Global MASTER-Net observations report
  12. LIGO/Virgo/KAGRA S250207bg: Update-5 NED Galaxies in the Localization Volume
  13. Fermi-LAT Gamma-ray Observations of IceCube-250302A
  14. EP 250304A: Optical counterpart detection by LCO
  15. EP250302A: 1.3m DFOT optical afterglow detection
  16. IceCube-250302A: Upper limits from a search for additional neutrino events in IceCube
  17. EP250304a: refined analysis of the EP-WXT and EP-FXT observations
  18. Konus-Wind detection of GRB 250222A
  19. EP250304a: Einstein Probe detection of an X-ray transient
  20. EP250302a: SAO RAS optical observations
  21. EP250302a : GIT optical follow-up
  22. EP250302a: optical observation from the INAF Asiago Observatory
  23. IceCube-241113A: MASTER flaring blazar 5BZB J1311+0853 with Zhirkov effect
  24. EP250302A: VLT near-infrared observations
  25. EP250302a: OHP/T193 optical and spectroscopic observations
  26. EP250302a: Einstein Probe detection of an X-ray transient
  27. EP250302a: Montarrenti Observatory optical detection
  28. Fermi GRB 250302A: Global MASTER-Net observations report
  29. EP250302a: FTW optical and NIR detection
  30. IceCube-250302A - IceCube observation of a high-energy neutrino candidate track-like event
  31. EP250228a: Optical observations with Kinder and Swift/UVOT
  32. Konus-Wind detection of GRB 250226A
  33. GRB 250225B: VLT/HAWKI near-infrared observations
  34. EP250227a: Einstein Probe detected of a fast X-ray transient
  35. EP250223a: J band upper limit by SYSU 80cm telescope
  36. EP250228a: Einstein Probe detection of an X-ray transient
  37. GRB 250226B: INTEGRAL SPI-ACS and PICsIT detection
  38. EP250226a/GRB 250226A: refined analysis of the EP-WXT and FXT observations
  39. Konus-Wind detection of GRB 250225B
  40. GRB 250225B: VLT/FORS2 candidate optical afterglow
  41. EP250226a/GRB 250226A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
  42. EP250226a / GRB 250226A: TRT optical counterpart observation
  43. LIGO/Virgo S250223dk: Swift XRT observations, 7 X-ray sources
  44. EP250226a/GRB 250226A: EP-WXT detection and FXT follow-up observation of an X-ray transient
  45. Fermi GRB 250226A: Global MASTER-Net observations report
  46. EP250225a: Einstein Probe detected of a fast X-ray transient
  47. Fermi GRB 250225A: Global MASTER-Net observations report
  48. EP250215A: J band upper limit by SYSU 80cm telescope
  49. LIGO/Virgo/KAGRA S250223dk and Swift/BAT-GUANO ID 762004910: AstroSat CZTI non-detection and upper limits
  50. GRB 250223C: Fermi GBM Final Real-time Localization
  51. GRB 250202B: VZLUSAT-2 detection
  52. GRB 250219A: EP-FXT afterglow detection
  53. EP250223a: 1.6m Mephisto and 50cm array observations
  54. LIGO/Virgo/KAGRA S250223dk and Swift/BAT-GUANO trigger with ID 762004910: Identification of a GW compact binary merger candidate possibly associated with a sub-threshold Swift/BAT-GUANO trigger
  55. EP250223a: NOT optical afterglow candidate
  56. Fermi GRB 250223A: Global MASTER-Net observations report
  57. EP250223a: Einstein Probe detection of an X-ray transient
  58. LIGO/Virgo/KAGRA S250206dm: Upper limits from IceCube neutrino searches
  59. GRB 250221A: continued Assy optical observations, brightening afterglow confirmation
  60. Konus-Wind detection of GRB 250221A
  61. GRB 250221A: Assy optical observations
  62. EP250220a: FTW optical and NIR observations and upper limits
  63. EP250220a: EP-FXT follow-up observations
  64. GRB 250221A: Swift-XRT refined Analysis
  65. EP250220a: Liverpool Telescope upper limits
  66. EP250220a: 1.6m Mephisto observations
  67. EP250220a: Liverpool Telescope optical upper limits
  68. GRB 250221A: Swift detection of a burst with an optical counterpart
  69. Swift GRB250221.15: Global MASTER-Net OT detection
  70. Swift GRB250221.15: Global MASTER-Net observations report
  71. Fermi Gamma-ray Burst Monitor trigger 761788229/250220993 is not a GRB
  72. GRB 250220B: Fermi GBM Final Real-time Localization
  73. Fermi Gamma-ray Burst Monitor trigger 761782146/250220923 is not a GRB
  74. GRB 250220A: Fermi GBM Final Real-time Localization
  75. EP250220a: Global MASTER-Net observations report
  76. EP250220a: EP-WXT detection of a fast X-ray transient
  77. Konus-Wind detection of GRB 250217C (short)
  78. GRB 250219A: OHP/T193 optical upper limit
  79. GRB 250219A: COLIBRÍ/DDRAGO Detection of the Optical Counterpart
  80. Konus-Wind detection of GRB 250215A / EP250215a
  81. GRB 250217C: COLIBRÍ/DDRAGO Upper Limits on the Optical Counterpart
  82. GRB 250217C: SVOM/GRM observation
  83. SVOM/sb25021804: SVOM detection of a long X-ray transient
  84. GRB 250213A: Swift-XRT observations
  85. GRB 250216A: AstroSat CZTI detection
  86. GRB 250217C: AstroSat CZTI detection of a short burst
  87. Fermi GRB 250217A: Global MASTER-Net observations report
  88. GRB 250216A: Fermi GBM Final Real-time Localization
  89. GRB 250215A: Swift-XRT refined Analysis
  90. EP250215a / GRB 250215A: AstroSat CZTI detection
  91. EP250215a: Global MASTER-Net observations report
  92. EP250215a: EP-WXT detection and FXT follow-up observation of an X-ray transient
  93. Fermi GRB 250215A: Global MASTER-Net observations report
  94. Fermi trigger No 761206993: Global MASTER-Net observations report
  95. EP250212a: Liverpool Telescope optical upper limits
  96. EP250212a: EP-WXT detection and FXT follow-up observation of a fast X-ray transient
  97. Fermi GRB 250212A: Global MASTER-Net observations report
  98. Fermi trigger No 760945500: Global MASTER-Net observations report
  99. GRB 250211B: A long GRB detected by INTEGRAL
  100. LIGO/Virgo/KAGRA S250206dm: GECKO Continued Observaiton with 7DT

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