Star

Primary of Susanowo.

Gliese 892 is a main sequence star in the constellation of Cassiopeia. It is smaller and less luminous than our Sun, with a spectral class of K3V, which makes it an orange-red hued star. Gl. 892 is relatively close to our system, with an estimated distance of 21.25 light years. This star is close to the limit of apparent magnitude that can still be seen by the unaided eye. The limit is considered to be magnitude 6 for most observers.

This star has a magnitude 9.4 companion at an angular separation of 106.6 arcseconds.

Primary of Itzamma.

It is a subgiant of spectral type G8 IV, meaning it is about to stop fusing hydrogen in its core and is starting the process of becoming a red giant. Because of that, Delta Pavonis is 22% brighter than the Sun even though the effective temperature of its outer atmosphere is lower, at 5,604 K. It has 99.1% of the Sun's mass and 122% of the Sun's radius. The surface convection zone extends downward to about 43.1% of the star's radius, but only contains 4.8% of the star's mass.

Spectroscopic examination of this star shows that it has a higher abundance of elements heavier than helium (or metallicity, as astronomers call it) than does the Sun. This value is typically given in terms of the relative ratio of iron (chemical symbol Fe) to hydrogen (H) as compared to the Sun's atmosphere.

The age of this star is in the range of 6.6–6.9 billion years old, and the star's luminosity has increased 60% since it became a zero-age main sequence star. It appears to be rotating slowly with a projected rotational velocity of 1.0 km s–1.

Primary of Chuvalete.

Spectral class: G8

More information

Primary of Gaheris.

Gliese 783 (279 G. Sagittarii) is a binary star system in the constellation of Sagittarius. It is 19.87 light years from Earth, and it has an absolute magnitude of +5.32. In space, Gliese 783 is approaching the solar system at a velocity of approximately 140 kilometers per second. At this rate, it will be 6.7 light years away in 40,000 years, and ten times brighter than its current state. The two stars are separated by an angle of 7.1", corresponding to a distance of about 43 AUs.

Spectral Class: K2, M3.5

Primary of Oisin.

The primary and secondary stars are nearly identical orange main sequence dwarves of spectral type K0/K1 and the tertiary star is an orange main sequence dwarf of spectral type K5.

Star C is separated from the A-B pair by 700 arc seconds, compared to a minimum of 4.6 arcsec for A-B, so it has a negligible effect on the movements of the A-B pair. Both A and B have active chromospheres.

The McDonald Observatory team has set limits to the presence of one or more planets around 36 Ophiuchi A with masses between 0.13 and 5.4 Jupiter masses and average separations spanning between 0.05 and 5.2 astronomical units, although the outermost stable orbits around either 36 Ophiuchi A or 36 Ophiuchi B are possible not beyond 1.5 AU.

Primary of Djuli.

The primary star in the Eta Cassiopeiae system has a stellar classification of G0 V, which makes it a G-type main-sequence star like the Sun. It therefore resembles what our Sun might look like if we were to observe it from Eta Cassiopeiae. The star has 97% of the mass of the Sun and 101% of the Sun's radius. It is of apparent magnitude 3.44, radiating 129% of the luminosity of the Sun from its outer envelope at an effective temperature of 6,087 K. It appears to be rotating at a leisurely rate, with a projected rotational velocity of 3.15 km s–1.

The cooler and dimmer magnitude 7.51 companion is of stellar classification K7 V; a K-type main sequence star. It has only 57% of the mass of the Sun and 66%[8] of the Sun's radius. Smaller stars generate energy more slowly, so this component radiates only 6% of the luminosity of the Sun. Its outer atmosphere has an effective temperature of 4,036 K. Compared to the Sun, this star, and the primary component, show only half the abundance of elements other than hydrogen and helium—what astronomer's term their metallicity.

This is a spectroscopic binary system, indicating that its binary nature was first detected by observing shifts in the spectrum. The pair are orbiting around each other over a period of 480 years.

Based on an estimated semimajor axis of 12″ and a parallax of 0.168″, the two stars are separated by an average distance of 71 AU, where an AU is the average distance between the Sun and the Earth. However, the large orbital eccentricity of 0.497 means that their periapsis, or closest approach, is as small as 36 AU, with an apoapsis of about 106 AUs. For comparison, the semi-major axis of Neptune is 30 AU.

Primary of Feng Po.

The primary star of the system (component A) is an orange dwarf star that may just have over three fourths the mass of the Sun, about 77 percent of its radius, and only 15.6 percent of its visual luminosity. It has a separation of 190 astronomical units from the binary components B and C, moving in an eccentric orbit that takes at least 2130 years to complete. Gliese 570 A is spectral type K4V and emits X-rays.

A binary system in their own right, components B and C are both rather dim red dwarf stars that have less mass, radius, and luminosity than the Sun. Component B is spectral type M1V, component C is spectral type M3V, and both emit X-rays.

An artists impression of Gliese 570 D showing the primary stars.
On January 15, 2000, astronomers announced that they had found one of the coolest brown dwarfs then known. Catalogued as Gliese 570 D (or rarely Gliese 570 d), it was observed at a wide separation of more than 1,500 astronomical unit from the triple star system. It has an estimated mass of 50 times that of Jupiter.

The status of Gliese 570 D as a brown dwarf was confirmed by Doppler spectroscopy at the Cerro Tololo Interamerican Observatory in Chile. The surface temperature of this substellar object was found to be a relatively cool 500 degrees Celsius, making it cooler and less luminous than any other known brown dwarf (including the prototype "T" dwarf), and classifying the object as a T7-8V brown dwarf. No X-rays have been reported from this brown dwarf.

Primary of Apocatequil.

Main sequence dwarf of spectral type G9. Formerly it was classified as K0, with the spectrum of this star serving as one of the stable anchor points by which other stars are classified. The radius has been directly measured using interferometery with the CHARA Array, which yields a result of 77.8% of the Sun's radius. It has 87% of the Sun's mass, but the luminosity of this star is only 43% that of the Sun. The projected rotation rate (v sin i) is relatively low at 1.5 km/s. It is considered a slightly metal-poor star, meaning that it has a lower proportion of isotopes with masses more than helium when compared to the Sun.

The temperature, luminosity and surface activity appear to vary slightly in a manner very similar to the sunspot cycle, although the full length of the cycle has not yet been determined. The total variability is among the lowest of all stars that have been measured by the Hipparcos spacecraft.

Primary of Keret.

70 Ophiuchi a binary star system located 16.6 light years away from the Earth. It is in the constellation Ophiuchus.

The primary star is a yellow-orange main sequence dwarf BY Draconis variable of spectral type K0, and the secondary star is an orange main sequence dwarf of spectral type K4. The two stars orbit each other at an average distance of 23.2 AUs. But since the orbit is highly elliptical (at e=0.499), the separation between the two varies from 11.4 to 34.8 AUs, with one orbit taking 83.38 years to complete.

Primary of Circe.

41 G. Arae or GJ 666 A is a binary star system in the constellation Ara. Although often called just 41 Arae, it is more accurate to call it 41 G. Arae, as the number 41 is the Gould designation (Flamsteed only covered the northern hemisphere).

The primary star in this system is a G-type main sequence star with a stellar classification of G8V. It has about 81% of the mass of the Sun, and 79% of the Sun's radius. The fainter member of the pair has a peculiar spectrum that shows a deficiency in metals, which, for astronomical purposes, are the elements heavier than Helium.

The two stars share a highly elliptical orbit that takes several centuries to complete. The estimates of the period range from 693 to 2,200 years, and the average separation of the two stars is about 210 AUs (or 210 times the average distance between the Earth and the Sun).