Stars similar to Albireo in angular size and color?

[lcd1080]

This image of Albireo shows Alberio A with an angular width of 6.5 arc seconds; I recorded it with a C11 and 2.5x barlow for an effective focal length of 7108mm. I'm looking for other colorful stars that have a large angular width (6 arc seconds or larger) due to the combination of their closeness to Earth and their large diameter (measured in kilometers rather than arc seconds). Can anyone suggest some stars that fit this criteria?

Thank you,
Peter Nerbun

[luigi]

145 CMa, a very beautiful double star and very similar to Albireo.

You can find it close to Wezen in Canis Major.

[lcd1080]

Thanks Luigi; that looks like it has potential for matching the colorful beauty of Albireo. I forgot to mention that I'm in the USA so 145 CMa transits at a fairly low elevation of 27 degrees but I'll give it a try.

The reason I wanted double stars with a large angular width is that I want to image them with a size similar to Mars using a long focal length SCT and 3x barlow; that way those stars would appear to have the size of a planet so as to be more than a mere point of light. The problem with 145 CMa is that its angular width is only 1/3000 of Alberio A's angular width; I calculated that based on the angular width of a spherical object being equal to 206265 * d/D where d is the actual diameter of the spherical object and D is the distance to the object. 145 CMa is 6300 light years away compared to Alberio's 390 light years which outweighs the fact that Alberio A's diameter is 213 Suns versus 154 CMa's diameter of 494 Suns. So I need to find a double star that is closer to Earth with a diameter similar to Alberio A. The interesting thing is that I measured Alberio A's angular width as 6.5 arc seconds in my image which corresponds to an actual diameter of 213 Suns however when I looked at my star atlas Alberio is listed with a diameter of only 59 Suns.

Thanks again,
Peter

[luigi]

If you are in the North Hemisphere what about Almach in Adromeda ?

[lcd1080]

Almach is great Luis! It's 18 times closer to Earth than 145 CMa and has a width of 82 Suns so it should appear as a two measurable disks when imaged through a 9000 mm focal length scope rather than as mere points of light.

Thank you!
Peter

[skysurfer]

You don't need to go to the northern hemisphere because the star is at declination 42 deg north, well visible from AU (even in MEL, 10 degrees high), particularly this time of the year. But it is not as spectacular as Albireo.
Close to it is a 8" Dobson challenge: NGC 891 'edge-on' cigar shaped galaxy.

Alpha Centauri is more spectacular : two very bright yellow stars.