2017 Visibility Forecast
78
Visibility Score
17.2
Expected /hr
16.3%
Moon Illum.
good
83.1°
Best Alt.
at 20:00
Radiant Altitude & Hourly Rate (Peak Night)
விளக்கம்
Medium strength shower with good rates for three nights around maximum. Can produce fireballs. Best from northern hemisphere at dawn.
வரலாறு
One of oldest known showers, Chinese records from 687 BC. Comet Thatcher orbital period ~415 years.
Radiant Position
Shower Properties
IAU CodeLYR
ClassMajor Shower
ZHR18
Velocity49.0 km/s
Speed ClassMedium (30-50 km/s)
Pop. Index (r)2.1
Radiant RA271.0°
Radiant Dec+33.6°
Peak Sol. Lng.32.32°
தாய் உடல்C/1861 G1 (Thatcher)
Parent Typecomet
Best Hemispherenorthern
2017 Dates
Activity StartApr 14
Activity EndApr 30
உச்ச தேதிApr 22
Moon PhaseWaxing Crescent
Moon Condition
good
Best Timepredawn
Characteristics
Moderate Rates