At the center of the Pleiades system, there are two stars HD 23463 and HD 23479, visually tiny, very close to each other. Let’s take a closer look to them.
Star HD 23463
Look into the enlarged corner photo the star one above is orange. Distance from earth: 432.24 light years. The star surface temperature is estimated in the range of 3700–5200 [K]. It does not belong to the constellation Taurus, its close on its border. Invisible for the naked eye, you need binoculars or a telescope to see it.
Star spectral class: K2 – its mass relative to the sun is 0.45 to 0.8 . So, it is “smaller” than our sun. The number of stars of this class is in the 12%, of the main sequence, so when we look on the sky, these stars occur quite frequently. When we look at the spectrum of a star, we will notice that these types of stars, have significant metal lines, where in astronomy we call metal with element heavier than helium.
Star HD 2347
It is a variable, eruptive star, blue in color. Distance from earth: 440.76 light years. It is estimated that its surface temperature is in the range of 7,500 and 10,000 [K]. For comparison, our sun has a surface temperature of around 5.770 [K]. So, it can be even twice as hot as our sun.
The spectral class of the star: A – The mass relative to the sun is 1.4 to 2.1 times greater. This type of stars only quantitatively feeds 0.6% of the main sequence. They are clearly visible in the sky. Sirius and Vega belongs to the type A main sequence stars.
On the enlarged photo it is below, right next to the HD 23463 star.
Main sequence stars: https://en.wikipedia.org/wiki/Main_sequence
Diagram Hertzsprunga-Russella: https://en.wikipedia.org/wiki/Hertzsprung%E2%80%93Russell_diagram
Location: La Palma 12.2020
Equipment: ATIK Horizon RGB, Hypergraph TS 150mm f/2,8 OTA PH6, CEM25P with small self made tuning
Processing: APP, RawTherapee, GIMP + add-ons (Linux)
Summary exposure: 6h
Calibration frames: Darks, Bias, Flats