C17: from Latin sīdereus, from sīdus a star, a constellation
sidereal in American English
(saɪˈdɪriəl)
adjective
1.
of or pertaining to the stars
2.
expressed in reference to the stars
Derived forms
sidereally (siˈdereally)
adverb
Word origin
< L sidereus < sidus (gen. sideris), a star < IE base *sweid-, to gleam > Lith svidù, to gleam
All related terms of 'sidereal'
sidereal day
the time between two successive passages of the vernal equinox across the meridian : it measures one rotation of the earth and equals 23 hours , 56 minutes , 4.1 seconds of mean solar time
sidereal hour
a 24th part of a sidereal day
sidereal time
time based upon the rotation of the earth with respect to the distant stars , the sidereal day being the unit of measurement
sidereal year
the period of time, the calendar year , containing 365 days or in a leap year 366 days. It is based on the Gregorian calendar, being divided into 12 calendar months , and is reckoned from January 1 to December 31
sidereal month
the time required for the moon to complete one revolution around the earth with respect to a fixed star : its average value is 27.32 days of mean solar time
sidereal period
the period of revolution of a body about another with respect to one or more distant stars
year
A year is a period of twelve months or 365 or 366 days, beginning on the first of January and ending on the thirty-first of December.