Definitions. The terms Unaccompanied minors, unaccompanied alien children, child migrants, child immigrants, unaccompanied migrant children, and juvenile immigrants are often used interchangeably and generally refer to immigrants who are under the age of 18 and are not under the care of a parent or legal guardian.
Regulus is 0.46 degree from the ecliptic, the closest of the bright stars, and is regularly occulted by the Moon. Occultations by the planets Mercury and Venus are possible but rare, as are occultations by asteroids. The last occultation of Regulus by a planet was on July 7, 1959, by Venus.
Once the period of a distant Cepheid has been measured, its luminosity can be determined from the known behavior of Cepheid variables. Then its absolute magnitude and apparent magnitude can be related by the distance modulus equation, and its distance can be determined.Cepheid variables can be used to measure distances from about 1kpc to 50 Mpc. For example, if an astronomer observed a Cepheid star with period of 34 days, comparing to previously measured Cepheids, its absolute magnitude is -5.65. If its apparent magnitude was +23.0, the astronomer could use the distance modulus equation: m - M = 5 log d - 5.