Attractive Doubles & Moon Shadows

[cloudsweeper]

4.40pm Tuesday, fairly clear, still. Moon high, ESE, 2 days past 1st quarter. 10” Dob in action.

MOON SHADOWS:

Plato near terminator, with jagged shadow on the floor of its eastern edge. Mount Pico to the south, casting a long shadow within M. Imbrium. Judging by Plato's diameter of 101km, the shadow from its wall was about 20km, so the shadow from Pico was about 25km (16 miles).

Nearby lay the Tenerife Mountains, stretching into the terminator.

Elsewhere, the Straight Wall and Alpine Valley were very clear.

x73 was used for these views, some shimmering. Still nice at x159. Very shimmery at x212, but one pit could be made out in Plato. x254 was too much.

FINE ARIES DOUBLES:

Started with Hamal and hopped to Σ240 - 8th mag pair, 4.8” apart. This sat at the bottom of an isosceles triangle. Going from x42 to x73 gave the split very clearly – close, matched, secondary at about 10 o'clock, very nice.

From Hamal again to 14 Ari – a triple of a 5th mag primary with a perfectly matched 8th mag pair at very wide separations from the primary of 93” and 105” in about the same direction, putting those two pleasingly close. This target sits between two pairs of widely separated prominent stars. The B and C stars could be seen as a separated, matched, faint pair at x42, both at 8 o'clock to the primary. View better at x73. The appearance and setting of this triple is most pleasing – highly recommended! (See sketch.)

Next target, Σ376 – another 8th mag pair, 7.1”, at a corner of a parallelogram of stars. I reached it by hopping from the Pleiades. At x42, the split was clear (though close), very well matched, side by side. Better at x73. Yet another attractive double!

By 5.50pm, the RACI, Rigel, and tube were all dewed up, so I took one last look at the now much brighter Moon, getting up to x318, and looking sharp but shimmering quite a lot. I dropped down to x212 for a more stable view with rich detail, but could see no pits in Plato. Finished at 6.00pm.

Wide and superwide doubles at low power can be very appealing!

Doug.

 

[domstar]

Very nice, Doug. Just popped in myself to warm my hand up. The starts are very sharp tonight. 

Thanks for the tip about wide doubles at low power- I often overlook them in favour of their tighter cousins.

[Epick Crom]

Nice job Doug👍. The Moon sure looked beautiful last night. I agree with you on 14 Arietis, it is a magnificent double star. Clear skies mate!

[Mr Spock]

Sounds like a good session.

[cloudsweeper]

Thanks everyone!  

Dom @domstar - yes, not-so-tight doubles are good, and with not needing great magnification, allow short-focus widefield fracs to be used.  Since these have fields in excess of 4deg for locating, they make hopping that much easier.  

I shall use the AR102S frac next time out!

Doug.

[wookie1965]

Nice one Doug some cracking doubles there I will have to check if I have them if not I will copy them thank you for posting. 

[cloudsweeper]

41 minutes ago, wookie1965 said:

Nice one Doug some cracking doubles there I will have to check if I have them if not I will copy them thank you for posting. 

Thanks Paul.  I've recently drawn up lists of doubles (by constellation, and with details) so I know exactly what I've seen and still need to track down.  A lot of work, but it makes things easier in the long run!

Doug.