26 relations: Am star, Apparent magnitude, Binary star, Boss General Catalogue, Bright Star Catalogue, Camelopardalis, Constellation, Day, Doppler effect, Durchmusterung, Epoch (astronomy), Giant star, Henry Draper Catalogue, Hipparcos, Iron, Orbital eccentricity, Orbital period, Parallax, Rotating ellipsoidal variable, Smithsonian Astrophysical Observatory Star Catalog, Spacecraft, Spectrum, Star, Stellar classification, University College London, Variable star designation.
An Am star or metallic-line star is a type of chemically peculiar star of spectral type A whose spectrum has strong and often variable absorption lines of metals such as zinc, strontium, zirconium, and barium, and deficiencies of others, such as calcium and scandium.
The apparent magnitude of a celestial object is a number that is a measure of its brightness as seen by an observer on Earth.
A binary star is a star system consisting of two stars orbiting around their common barycenter.
Boss General Catalogue (GC, sometimes General Catalogue) is an astronomical catalogue containing 33,342 stars.
The Bright Star Catalogue, also known as the Yale Catalogue of Bright Stars or Yale Bright Star Catalogue, is a star catalogue that lists all stars of stellar magnitude 6.5 or brighter, which is roughly every star visible to the naked eye from Earth.
Camelopardalis is a large but obscure constellation of the northern sky representing a giraffe.
Christmas is an annual festival commemorating the birth of Jesus Christ,Martindale, Cyril Charles.
The Christmas season, also called the festive season, or the holiday season (mainly in the U.S. and Canada; often simply called the holidays),, is an annually recurring period recognized in many Western and Western-influenced countries that is generally considered to run from late November to early January.
Christmas Eve is the evening or entire day before Christmas Day, the festival commemorating the birth of Jesus.
Christmas traditions vary from country to country.
A constellation is a group of stars that are considered to form imaginary outlines or meaningful patterns on the celestial sphere, typically representing animals, mythological people or gods, mythological creatures, or manufactured devices.
A day, a unit of time, is approximately the period of time during which the Earth completes one rotation with respect to the Sun (solar day).
The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave in relation to observer who is moving relative to the wave source.
In astronomy, Durchmusterung or Bonner Durchmusterung (BD), is the comprehensive astrometric star catalogue of the whole sky, compiled by the Bonn Observatory (Germany) from 1859 to 1903.
In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as the celestial coordinates or elliptical orbital elements of a celestial body, because these are subject to perturbations and vary with time.
A giant star is a star with substantially larger radius and luminosity than a main-sequence (or dwarf) star of the same surface temperature.
The Henry Draper Catalogue (HD) is an astronomical star catalogue published between 1918 and 1924, giving spectroscopic classifications for 225,300 stars; it was later expanded by the Henry Draper Extension (HDE), published between 1925 and 1936, which gave classifications for 46,850 more stars, and by the Henry Draper Extension Charts (HDEC), published from 1937 to 1949 in the form of charts, which gave classifications for 86,933 more stars.
Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993.
Iron is a chemical element with symbol Fe (from ferrum) and atomic number 26.
New Year is the time or day at which a new calendar year begins and the calendar's year count increments by one.
New Year's Day, also called simply New Year's or New Year, is observed on January 1, the first day of the year on the modern Gregorian calendar as well as the Julian calendar.
In the Gregorian calendar, New Year's Eve (also known as Old Year's Day or Saint Sylvester's Day in many countries), the last day of the year, is on 31 December which is the seventh day of Christmastide.
The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle.
The orbital period is the time a given astronomical object takes to complete one orbit around another object, and applies in astronomy usually to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines.
Rotating ellipsoidal variables are a class of variable star.
The Smithsonian Astrophysical Observatory Star Catalog is an astrometric star catalogue.
A spacecraft is a vehicle or machine designed to fly in outer space.
A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without steps, across a continuum.
A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity.
In astronomy, stellar classification is the classification of stars based on their spectral characteristics.
University College London (UCL) is a public research university in London, England, and a constituent college of the federal University of London.
Variable stars are designated using a variation on the Bayer designation format of an identifying label (as described below) combined with the Latin genitive of the name of the constellation in which the star lies.
2018 has been designated as the third International Year of the Reef by the International Coral Reef Initiative.
2019 (MMXIX) will be a common year starting on Tuesday of the Gregorian calendar, the 2019th year of the Common Era (CE) and Anno Domini (AD) designations, the 19th year of the 3rd millennium, the 19th year of the 21st century, and the 10th and last year of the 2010s decade.