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View Full Version here: : Epsilon Monoceros (Double Star)


Tropo-Bob
13-01-2018, 10:38 AM
I used this as a reference star when star hoping to the Rosette Nebula, but the double was a worthy object for viewing. Epsilon Monoceros has a variety of names, including 8 Monoceros.

The components are unequal in brightness and were of differing colours. They were an easy wide split with my Tak 100D at 99x (using an LE 7.5mm Tak EP).

I judged the primary to be a very light yellow, almost white.

The secondary was more complex. I finally settled on grey, which was very unsatisfying as I have never heard of a star being described as grey.

Checking various references this morning, I found that Sissy Hass in her book Double Stars quotes describes 8 Monocerost as: "Striking. A brilliant white star almost touched by a silvery smokepuff.." I call silver vehicles as being grey, so I felt more reassured about my colour description when reading this. Nevertheless, Collins Stars & Planets (2nd Edition) describe the colours as being yellow & blue. I have noticed other colour determinations, so it is interesting to note the discrepancies.

Another inconsistency is that some sources say its distance is 121 light years, whereas others say it is in the 70s.

More information:
https://en.wikipedia.org/wiki/Epsilon_Monocerotis
https://www.universeguide.com/star/epsilonmonocerotisb

Tinderboxsky
19-01-2018, 11:35 AM
I re-vsisted this double last night to see what colours I was perceiving. I saw the primary as a bright, light yellow, more yellow than white and the the faint companion a pale smokey yellow.
Yes, it is a fine double with a wide split at 100X which dominates a rich field of many stars. There are many fine optical double and triple stars in the field. Did you see the faint red star about 5-10 arc minutes away at about 300 degree angle?

bigjoe
20-01-2018, 12:17 AM
Hadn't visited this for a while Bob....its an easy starhop from Betelguese in Orion, and so close to the Rosette.

I remember it as bright yellow white/pale bluish gray...though spent too much time on the spectacular triple Beta Monocerotis nearby, in a large SCT.

At Mags 4.4, 6.6 and Sep 12.1" , its an easy and pretty split in almost any scope.

Look forward too a revisit in the next few days

Image attached from Skysafari plus.

bigjoe.

Tropo-Bob
26-01-2018, 08:40 AM
Thanks Joe & Steve for you observations.

Steve, I failed to notice the red star. I like red stars, so I will look for it when possible.