The star is a foreground object in our galaxy, in the constellation Canes Venatici, the Hunting Dogs. Interestingly, this faint constellation is well placed for northern observers: the star is located just "below" the Big Dipper!
Here you can see a picture of the galaxy and the star, although the orientation of the picture is different. In the picture that I've provided a link to, the bright star is at upper left. The star has a designation, HD 106556. Its V magnitude (visual magnitude, or brightness as measured through a yellow-green filter) is 7.28. That means that the star is too faint to be spotted without optical aid. The faintest stars that can be spotted with the naked eye by people with good eyesight, observing from a very dark site, have a V magnitude of about 6.0.
However, HD 106556 is an intrinsically bright star. It is a red giant star, a star that perhaps started out much like our own Sun, but which has since used up all the hydrogen in its core and moved its hydrogen fusion "outward" into a shell around its core, causing its outer layers to swell mightily.
HD 106556 is, interestingly, slightly similar to the Sun in that it belongs to spectral class G just like the Sun, although HD 106556 is cooler than the Sun. Its spectral class is G5II, whereas the Sun's spectral class is G2V. Although I just described HD 106556 as a red giant, its color is too similar to that of the Sun to be called red. We might call it a yellow giant.
HD 106556 has a very small
parallax. That means that when the satellite Hipparcos scanned the sky in order to find out how much the stars appeared to move in relation to one another as the Earth about 300 million kilometers in the sky in six months, HD 106556 moved so little that Hipparcos couldn't be sure it could detect any parallax at all. However, HD 106556 most definitely belongs to our own galaxy, and my software assumes that it is 2250 ± 900 light-years away, and that it is several hundred times as bright as the Sun.
Interestingly, there is another star which is of interest here, which is seen right next to the disk of NGC 4217. This star is too faint to have a HD number, but it has a SAO number, SAO 44095. It also has a Hipparcos number, HIP 59810. The V magnitude of this star is 8.99 or 9.00. Its spectral class, according to my software, is G8III, so this is another giant star which is fusing hydrogen to helium in a shell around its core. It is however clearly fainter than HD 105665. Not only does it look fainter to us in the sky, but it is probably a little nearer than HD 106556, probably less than a thousand light-years. My software estimates that its absolute V magnitude is about fifteen times that of the Sun!
Ann
