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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').
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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"

28295 results found.

  1. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
  2. GRB 251106A: MASTER optical observations
  3. GRB 251025C: TERI Gamma-ray detection
  4. GRB 251016B: TERI Gamma-ray detection
  5. GRB 251016A: TERI Gamma-ray detection of a short burst
  6. GRB 250920C: TERI Gamma-ray detection
  7. Fermi trigger No 784034269: Global MASTER-Net observations report
  8. EP251102a: Xinglong 2.16-m clear-band observations of the optical counterpart
  9. GRB 251105A: Fermi GBM Observation
  10. GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
  11. GRB 251104A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  12. Fermi GBM Sub-Threshold Detection of GRB 251105B
  13. GRB 251103B: Swift/UVOT Upper Limits
  14. LIGO/Virgo/KAGRA S251105aj: Identification of a GW compact binary merger candidate
  15. GRB 251103B: Fermi GBM observation
  16. GRB 251103A: WFST optical observations
  17. GRB 251103A: OHP/T193 optical observations
  18. GRB 251103A: Xinglong 2.16m optical detection
  19. GRB 251103A: KAIT optical observations
  20. GRB 251103B: Nanshan/HMT optical upper limit
  21. GRB 251013C: 7DT detection and Medium-band SED of Afterglow
  22. GRB 251103A: Swift/BAT-GUANO arcminute localization of a burst
  23. GRB 251103B: MITSuME Akeno optical upper limits
  24. GRB 251103B: Swift-XRT refined Analysis
  25. LIGO/Virgo/KAGRA S251103f: Identification of a GW compact binary merger candidate
  26. EP251102a: NIR observations with WINTER
  27. GRB 251103A: J-band detection with WINTER
  28. GRB 251103B: GROWTH-India Telescope optical upper limits
  29. GRB 251103A: Kilonova-Catcher optical afterglow detection
  30. GRB 251103B: Enhanced Swift-XRT position
  31. GRB 251103B: Swift detection of a burst
  32. GRB 251103A: Swift/UVOT Detection
  33. GRB 251103A: Fermi GBM Observation
  34. GRB 251103A: Swift-XRT afterglow detection
  35. LIGO/Virgo/KAGRA S251031cq: Updated Sky localization
  36. GRB 251103A: SVOM/COLIBRÍ (FM-GFT) optical observations
  37. EP251102a: Einstein Probe detection of a fast X-ray transient
  38. EP251102a (WXT 11900459650): LCO observations confirm COLIBRÍ candidate
  39. GRB 251103A: LCO optical observation
  40. EP251102.890: COLIBRÍ optical counterpart candidate
  41. GRB 251026A: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical counterpart
  42. GRB 251103A: LCO optical afterglow detection
  43. GRB 251103A: NOT optical afterglow candidate
  44. GRB 251031A: Fermi GBM Observation
  45. LIGO/Virgo/KAGRA S251031cq: Identification of a GW compact binary merger candidate
  46. GRB 251031A: Swift/BAT-GUANO localization skymap of a burst
  47. GRB 251031A: BALROG localization (Fermi Trigger 783588065 / GRB 251031306)
  48. GRB 251025C: SVOM/GRM observation
  49. GRB 251028A: SVOM/GRM observation
  50. GRB 251028A: Fermi GBM Observation
  51. GRB 251022A: Swift-XRT confirmation of fading
  52. GRB 250926A: VZLUSAT-2 detection
  53. GRB 251026B: Fermi GBM Observation
  54. GRB 251026A/EP251026a: SVOM/VT optical counterpart
  55. GRB 251028B: Swift/BAT-GUANO localization skymap of a burst
  56. GRB 251028B: Glowbug gamma-ray detection
  57. GRB 251028A: Glowbug gamma-ray detection
  58. GRB 251025B: GROWTH-India Telescope continued multiband optical observations and rebrightening
  59. GRB251026B: PRIME H-band upper limit
  60. GRB251025B: 3.6m DOT Optical Observations
  61. GRB 251028A: BALROG localization (Fermi Trigger 783314796 / GRB 251028143)
  62. GRB 251028A: MAXI/GSC detection
  63. SVOM trigger sb25102702/GRB 251027A is not a GRB
  64. IceCube-251025A: Upper limits from a search for additional neutrino events in IceCube
  65. GRB 251013C : 3.4-m telescope of Iranian National Observatory (INO340) optical observations
  66. GRB 251026B: Swift-XRT observations of GOTO25jgl/AT2025absf
  67. GRB 251025C: Glowbug gamma-ray detection
  68. Fermi-LAT Gamma-ray Observations of IceCube-251025A
  69. GRB 251027A: Swift-XRT observations
  70. EP251027.145: COLIBRÍ optical upper limits
  71. GRB 251022A: SVOM/GRM observation
  72. GRB 251026A/EP251026a: Einstein Probe detection of a fast X-ray transient
  73. GRB 251027A: LCO optical upper limit
  74. GRB 251027A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  75. GRB 251017A: Mondy AZT-33IK and Koshka Zeiss-1000 optical observations
  76. GRB 251023B / EP251023b: Mondy optical upper limit
  77. GRB 251017A: INASAN-Kislovodsk optical observations
  78. GRB 251026A: Mondy optical upper limit
  79. GRB 251025B: Mondy optical observations
  80. GRB 251025B: Kilonova-Catcher optical afterglow detection
  81. GRB 251025B: VLT/MUSE spectroscopic redshift z = 2.003
  82. GRB 251027A: SVOM detection of a faint burst
  83. EP251023a: Mondy optical observations
  84. GRB 251025B: MAO/AZT-22 optical observations
  85. LIGO/Virgo/KAGRA S251026bn: Updated Sky localization
  86. Fermi GRB 251025C: Global MASTER-Net observations report
  87. LIGO/Virgo/KAGRA S251026bn: Identification of a GW compact binary merger candidate
  88. GRB 251026A: Swift-XRT observations
  89. GRB 251025B: OHP/T193 optical detection
  90. GRB 251025B: J-band detection with WINTER
  91. GRB 251026A: SVOM/C-GFT upper limit
  92. IceCube-251025A: DDOTI Optical Upper Limit
  93. GRB 251026A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  94. GRB 251026A: SVOM detection of a long burst
  95. GRB 251025B: SVOM/COLIBRÍ (FM-GFT) strong rebrightening of the optical counterpart
  96. GRB 251023A: SVOM/GRM observation
  97. GRB 251025B: ULL-ASTRO-MASTER optical counterpart detection with IAC80 telescope at Teide Observatory
  98. GRB 251025B: GROWTH-India Telescope optical observations
  99. GRB 251024A: Swift/UVOT Upper Limits
  100. GRB 251025B: Swift-XRT afterglow detection

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