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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"

21799 results found.

  1. GRB 251117A: SVOM/GRM observation of a short burst
  2. GRB 251117A: Fermi-LAT detection
  3. LIGO/Virgo/KAGRA S251117dq: Identification of a GW compact binary merger candidate
  4. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  5. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  6. EP251023a: Assy AZT-20 optical observations
  7. EP251023a: UAFO and AbAO optical observations
  8. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  9. GRB 251025B: further Mondy optical observations
  10. GRB 251111A: Mondy optical upper limit
  11. LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
  12. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  13. GRB 251116B: LCO optical upper limits
  14. GRB 251116C: LCO optical upper limits
  15. GRB 251116C: SVOM detection of a burst
  16. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  17. GRB 251115A: Fermi-LAT detection
  18. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  19. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  20. GRB 251113A: AstroSat CZTI detection
  21. Konus-Wind detection of GRB 251108C
  22. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  23. IPN triangulation of GRB 251108C
  24. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  25. GRB 251111A: SVOM/ECLAIRs refined analysis
  26. GRB 251025B: SVOM/ECLAIRs refined analysis
  27. GRB 251112A: Swift/UVOT Upper Limits
  28. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  29. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  30. Swift Trigger 1413695: a possible GRB 251112A
  31. GRB251111A: 1.3m DFOT optical upper limit
  32. LIGO/Virgo/KAGRA S251112cm: Identification of a GW compact binary merger candidate
  33. GRB 251111A: Swift-XRT afterglow detection
  34. GRB 251111A: SVOM/VT optical observations with X-band data
  35. GRB 251111A: SVOM/VT optical observations with VHF data
  36. GRB 251111A: LCO optical observation
  37. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  38. GRB 251111A: SVOM detection of a soft burst
  39. GRB 251106A: Swift/UVOT Upper Limits
  40. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  41. GRB 251105A: AstroSat CZTI detection
  42. LIGO/Virgo/KAGRA S251108fi: Identification of a GW compact binary merger candidate
  43. GRB 251102B: SVOM/GRM observation
  44. LIGO/Virgo/KAGRA S251108dn: Identification of a GW compact binary merger candidate
  45. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) fading of the optical counterpart
  46. GRB 251106A: Swift-XRT afterglow detection
  47. GRB 251106A: Kilonova-Catcher optical upper limit
  48. Fermi GBM Sub-Threshold Detection of GRB 251106A
  49. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
  50. GRB 251106A: MASTER optical observations
  51. EP251102a: Xinglong 2.16-m clear-band observations of the optical counterpart
  52. GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
  53. GRB 251104A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  54. GRB 251023A: SVOM/ECLAIRs detection of a burst through targeted search
  55. GRB 251103B: Swift/UVOT Upper Limits
  56. LIGO/Virgo/KAGRA S251105aj: Identification of a GW compact binary merger candidate
  57. GRB 251105A: Fermi GBM Final Real-time Localization
  58. GRB 251103B: Fermi GBM observation
  59. GRB 251104A: SVOM detection of a burst
  60. GRB 251103A: WFST optical observations
  61. EP251102a: OHP/T193 optical observations
  62. GRB 251103A: OHP/T193 optical observations
  63. GRB 251103A: Xinglong 2.16m optical detection
  64. GRB 251103A: KAIT optical observations
  65. GRB 251103B: Nanshan/HMT optical upper limit
  66. GRB 251013C: 7DT detection and Medium-band SED of Afterglow
  67. GRB 251103A: Swift/BAT-GUANO arcminute localization of a burst
  68. GRB 251103B: MITSuME Akeno optical upper limits
  69. LIGO/Virgo/KAGRA S251103f: Identification of a GW compact binary merger candidate
  70. EP251102a: NIR observations with WINTER
  71. GRB 251103A: J-band detection with WINTER
  72. GRB 251103B: GROWTH-India Telescope optical upper limits
  73. GRB 251103A: Kilonova-Catcher optical afterglow detection
  74. GRB 251103B: Enhanced Swift-XRT position
  75. GRB 251103B: Swift detection of a burst
  76. GRB 251103A: Swift/UVOT Detection
  77. GRB 251103A: Swift-XRT afterglow detection
  78. GRB 251103A: SVOM/COLIBRÍ (FM-GFT) optical observations
  79. EP251102a: Einstein Probe detection of a fast X-ray transient
  80. GRB 251025B: OHP/T193 optical upper limit
  81. EP251102a (WXT 11900459650): LCO observations confirm COLIBRÍ candidate
  82. GRB 251103A: LCO optical observation
  83. EP251102.890: COLIBRÍ optical counterpart candidate
  84. GRB 251102A: AstroSat CZTI detection
  85. GRB 251026A: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical counterpart
  86. GRB 251103A: LCO optical afterglow detection
  87. GRB 251103A: NOT optical afterglow candidate
  88. LIGO/Virgo/KAGRA S251031cq: Identification of a GW compact binary merger candidate
  89. GRB 251031A: Swift/BAT-GUANO localization skymap of a burst
  90. Konus-Wind detection of GRB 251028A
  91. GRB 251025C: SVOM/GRM observation
  92. GRB 251028A: GECAM-B detection
  93. GRB 251028A: SVOM/GRM observation
  94. GRB 251022A: Swift-XRT confirmation of fading
  95. GRB 250926B: VZLUSAT-2 detection
  96. GRB 250926A: VZLUSAT-2 detection
  97. GRB 250925A: VZLUSAT-2 detection
  98. GRB 251026A/EP251026a: SVOM/VT optical counterpart
  99. GRB 251028B: Swift/BAT-GUANO localization skymap of a burst
  100. GRB 251025B: GROWTH-India Telescope continued multiband optical observations and rebrightening

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