A Mak and seven red (sometimes orange) dwarfs

[Nik271]

I find red dwarfs fascinating. These are stars which will last for incredibly long time, hundreds, even thousands of billions of years. Most of the stars in the galaxy are red dwarfs, but we don't see many of them because they are small and dim. None are visible with the naked eye. Some well-known red dwarfs are Proxima Centauri, 40 Eridani C and Barnard's star. There are reasons to believe that K-class orange dwarfs are the most suitable stars to search for alien life, because of their stability and longevity. Tonight I decided to visit some 'bright' red dwarfs (above 10-th magnitude) which are part of a double system, ideally paired with another red or orange dwarf.

To split dim doubles I knew I need aperture, so used my Skymax 127 on AZ5. To simplify things even further I decided to use only two EPs: a 20mm Svbony and a 10mm Hyperion giving x75 and x150 respectively. Observing was done from the back of the garden between 10pm and 11pm.

The first double on my list was STF 2398, a pair of 9-th and 10-th magnitude red dwarfs 11.5 light years away. The separation is 11''. Split aready at x75, the colour was even more prominent with the 10mm Hyperion. The pair was easy to find,  1 degree east of Omicron Draconis, which is itself a wide optical double: G class yellow primary and a K class orange dwarf secondary. 

Next on my list was Groombridge 34, another pair of red dwarfs similar distance away, 11.6 light years. This one was tricky. I found the location easy enough, 20' north from 26 And, but at first I saw an orange and a dimmer white/blue star at least an arcminute away. After some double checking I realised the white star is just an optical double sharing the field and I have to look harder at the orange star to spot the dim companion. The primary is mag 8 while the secondary is mag 11.3. Sure enough once I relaxed my eye I spotted the dim companion with averted vision.  It's well separated from the primary at 34'',  the best view was at x75.

Last on my list was STT 547, a red dwarf and K-class orange dwarf about 38ly away. They are 1 degree west of 22 And. I found this pair quite easy even though they are  5'' apart as the two stars have the same fairly bright 9-th magnitude. I could separate them even at x75, at x150 while the separation was wider, the colour was dimmer.

While in the area I visited another nearby double: BU997, a mag 7.6 primary and mag 9 secondary 4'' apart. This one was hiding at x75 but showed readily at x150.  As far as I know none of them is a red dwarf. At 200+ ly away they must be larger stars to see them at their apparent brightness. 

My neighbours decided to switch on their garden lights and made the stars almost invisible 😞 Time to pack up.

I finished with a look at Saturn with several moons on display: Rhea, Titan and Iapetus.

Clear skies,

Nik

 

Edited September 5, 2023 by Nik271
typos corrected

[RobertI]

Fascinating stuff. 👍

[Nik271]

One more easy to see red dwarf: Gilese (GJ) 752. This one is in the same field of view as 22 Aquilae. It is magnitude 9 and about 19 light years away. Interestingly it is also part of a binary system with another red dwarf: Van Biesbroeck's star (VB10, same as V 1428 Aquilae) , which is one of the smallest and dimmest proper stars known. At mag 17 it can only be seen photographically. Its mass is under 1% of the mass of the Sun!

I observed GJ752 last night with my 102mm ED refractor and the 24mm Hyperion EP. Hopped from Delta Aql to 22 Aql and GJ 752 was immediately visible as a dim red star in the same FoV. I did not try for the companion 🙂

Edited September 6, 2023 by Nik271

[Epick Crom]

14 hours ago, Nik271 said:

One more easy to see red dwarf: Gilese (GJ) 752. This one is in the same field of view as 22 Aquilae. It is magnitude 9 and about 19 light years away. Interestingly it is also part of a binary system with another red dwarf: Van Biesbroeck's star (VB10, same as V 1428 Aquilae) , which is one of the smallest and dimmest proper stars known. At mag 17 it can only be seen photographically. Its mass is under 1% of the mass of the Sun!

I observed GJ752 last night with my 102mm ED refractor and the 24mm Hyperion EP. Hopped from Delta Aql to 22 Aql and GJ 752 was immediately visible as a dim red star in the same FoV. I did not try for the companion 🙂

Fascinating information Nik, thanks for this I had never heard of this star before. I'll hunt it down tonight!

 

Clear Skies

Joe

[The60mmKid]

Thanks for the wonderful report! I'm jotting these down these to observe soon 😎

[Mr Magoo]

Very interesting information about red dwarfs. I will be scouring the Web for more detail, this is the kind of stuff that fires up my imagination.  Great report, thank you.

[SwiMatt]

Great report! Extremely fascinating. Thank you Nik

[Nik271]

11 hours ago, Mr Magoo said:

Very interesting information about red dwarfs. I will be scouring the Web for more detail, this is the kind of stuff that fires up my imagination.  Great report, thank you.

Wikipedia has a lot of information and lists of red dwarfs. My next red dwarf to observe is Gilese 876 in Aquarius.

https://en.wikipedia.org/wiki/Gliese_876

Apparently it has at least 4 detected planets including a super Earth.