Passage: Gamma Arietis, with a common name of Mesarthim, is a binary star with two white-hued components, located in a rich field of magnitude 8-12 stars. Its traditional name has conflicting derivations. It may be derived from a corruption of "al-sharatan", the Arabic word meaning "pair" or a word for "fat ram". However, it may also come from the Sanskrit for "first star of Aries" or the Hebrew for "ministerial servants", both of which are unusual languages of origin for star names. Along with Beta Arietis, it was known to the Bedouin as "qarna al-hamal". The primary is of magnitude 4.59 and the secondary is of magnitude 4.68. The system is 164 light-years from Earth. The two components are separated by 7.8 arcseconds, and the system as a whole has an apparent magnitude of 3.9. The primary has a luminosity of  and the secondary has a luminosity of ; the primary is an A-type star with an absolute magnitude of 0.2 and the secondary is a B9-type star with an absolute magnitude of 0.4. The angle between the two components is 1°. Mesarthim was discovered to be a double star by Robert Hooke in 1664, one of the earliest such telescopic discoveries. The primary, γ1 Arietis, is an Alpha² Canum Venaticorum variable star that has a range of 0.02 magnitudes and a period of 2.607 days. It is unusual because of its strong silicon emission lines.
How many points difference is there between primary magnitude and secondary magnitude? Which start has a higher absolute magnitude, A-type star or B9-type star?