Saturday, March 18, 2017

imaged 15 Mon (Halifax)

BGO captured multi-star system 15 Monocerotis, aka Σ950, centered on GSC 00750-1865. I viewed this system in early-April '13 but did not identify all of the elements.

multi-star system 15 Mon in luminance

Luminance only, 2 seconds subexposures, 10 stacked shots. FITS Liberator, GIMP. North is up; east is left.

The B star is too close to bright A to split, unfortunately.

C is deliciously close to A, to the north.

D is easily spotted to the right of C, north-west of A. It is very faint. I had not seen this before.

Not sure what to say about E. There certainly seems to be a magnitude 11 star is the correct place. But SkyTools 3 Pro says the variable V343 Mon is south of E. Nothing shows in the image. Perhaps SkyTools is wrong in showing 2 stars; maybe there's only 1 and it is the variable and it was quite dim when I looked before.

F and G are south of E, brighter than E. F is on the east while dimmer G is to the west. This pairing is well away from AB to the south-west. F is slightly further away than E.

South-east of AB is the touching, unequal pairing of H and I.

South-west of HI is J, almost due south of AB. J appears the same mag as G. This star is also known as D11.

K is north-east of AB, opposite E, slightly closer than E. K is dimmer than G but brighter than C.

L and M are the close pair of equal stars to the east-south-east of AB. They also seem the same brightness of G. The M star appears to have another designation: Σ952.

N is south of HI. It is much dimmer. I had not seen N before.

O is due east of N. Very slightly brighter than N. aka V810 Mon.

Finally, U is to the north of A, B, and C. U looks to be the same magnitude as N. aka JRN 30.

That was awesome. Spotted 2, possibly 3, more stars of this interesting system.

To the east-south-east of the 15 Mon system is the bright triangle of HD 262066. This is a quad. A and B are on top of one another at the south apex and not splittable in the image. Too bad. I did not split them in 2013. This will remain on the View Again list. C is the west point and is brighter. D is north-east of HD 262066 AB.

To the south-west of 15 Mon is V684, a quintuple. A, B, and C, form a compact triangle. D is to the south-east of A, slightly dimmer than the primary. E is to the north-east of A, about the same separation as AD. E is dimmer than C.

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