I asked this in a thread in Observing but didn't get an answer so I'm dropping it in here.
I caught both the E & F stars last February in Tx with my 2080. Didn't know what to make of it as I wasn't aware of them before that. I took a peek for them last week with my 1100 here MI and couldn't see them. Seeing was fair and I expected to see them. (Though the seeing was not as good I had 3" of aperture.)
In the Sky&Telescope article that DLuders linked they state that these are binaries:
"They're both eclipsing binaries: V1016 Ori ranges from magnitude 6.7 to 7.7 over a period of 65 days and BM Ori from 7.9 to 8.7 every 6.5 days. With its much shorter period, it should be relatively easy to catch BM at both maximum and minimum sometime this season."
So I am wondering if it was poor seeing or do these stars sneak ought of sight???
Hold on here, JD. I'm just a bit confused by your post, which starts out talking about the E and F stars in the Trapezium and then suddenly appears to shift to BM and V1016 ORI. To me, at least, it sounds as if you believe that the minute stars E and F are identical with the two variables...in spite of your stating that the variables are actually both relatively bright, obvious stars. V1016 ORI is, in fact, identical with Theta 1A ORI, the brightest star in the Trapezium, while BM ORI is star B in the Trapezium. Both are obvious targets with even the smallest telescopes. Now I don't have any idea of whether stars E and F are variable, but their placement among the vastly brighter members of the Trapezium, their decided faintness and the glowing background of the nebula, are usually most responsible for their elusiveness.
As to catching eclipses of BM ORI simply by chance, the odds of this are very unlikely. The eclipses take up only a quite limited fraction of the star's light curve, so witnessing the the star in eclipse usually requires both foreknowledge and careful planning. I know this to be true because I monitored several eclipses of BM in the past.
Edited by BrooksObs, 13 January 2018 - 08:45 AM.