LHS 1723

LHS 1723 is a nearby red dwarf star of spectral type M4.0, located in constellation Eridanus at 17.4 light-years from Earth.

History of observations

The discovery name of this star is LP 656-38, which indicates that its discovery was published between 1963 and 1981 in University of Minnesota, Minneapolis. "LP" means "Luyten, Palomar".

LHS 1723 is known at least from 1979, when catalogues of high proper motion objects LHS and NLTT were published by Willem Jacob Luyten, and this object was included to these catalogues.

Distance measurement

In 1982 Wilhelm Gliese published photometric distance of LHS 1723 (0.161 mas), and in 1991 it was included to the 3rd preliminary version of catalogue of nearby stars by Gliese and Jahreiss as NN 3323 (also designated as GJ 3323) with photometric parallax 6993790246300208545♠163.0±26.0 mas.

Its trigonometric parallax remained unknown until 2006, when it was published by RECONS team. The parallax was 6993911061869541042♠187.92±1.26 mas.

References

ADS 48

ADS 48 is a multiple star system in the constellation of Andromeda consisting of 7 stars. The components, in order from A to G, have apparent visual magnitudes of 8.83, 9.00, 13.30, 12.53, 11.68, 9.97, and 13.00.

ADS 48A and ADS 48B are in orbital motion around each other while ADS 48F is a common proper motion companion. The others are unassociated background stars.

References

Innes' star

Innes' star (Gliese 422) is an M3.5-type red dwarf, located in constellation Carina. It has around 35% of the mass of the Sun, yet only 1.1% of its luminosity, and an estimated surface temperature of 3,323 K.

It is known for the fact that it had once been considered one of the nearest stars to Earth, due to erroneously measured parallax. The estimated distance was less than 10 light-years in the following studies:

Altair

Altair (α Aquilae, α Aql) is the brightest star in the constellation Aquila and the twelfth brightest star in the night sky. It is currently in the G-cloud. Altair is an A-type main sequence star with an apparent visual magnitude of 0.77 and is one of the vertices of the Summer Triangle (the other two vertices are marked by Deneb and Vega). It is 16.7 light-years (5.13 parsecs) from Earth and is one of the closest stars visible to the naked eye.

Altair rotates rapidly, with a velocity at the equator of approximately 286 km/s. A study with the Palomar Testbed Interferometer revealed that Altair is not spherical, but is flattened at the poles due to its high rate of rotation. Other interferometric studies with multiple telescopes, operating in the infrared, have imaged and confirmed this phenomenon.

Characteristics

Altair is located 16.7 light-years (5.13 parsecs) from Earth and is one of the closest stars visible to the naked eye. Along with Beta Aquilae and Gamma Aquilae, it forms the well-known line of stars sometimes referred to as the Family of Aquila or Shaft of Aquila.