Andrew Cooper
Nov 13, 2020    Waikoloa, HI (map)
20cm f/6 Newtonian, Cave Astrola @ 76x
Seeing: 5 Transparency: 6 Moon: 0%

Σ 239 is a pretty binary, the 7th magnitude DL Tri, a yellow with the 8th magnitude SAO 75264, a rich yellow easily visible 14" southwest, 10 Tri is 21' southeast

Gaia DR2 data shows well matched parallax and proper motion for the two component stars

Captain William Henry Smyth
Dec 2, 1834    No. 6 The Crescent, Bedford, England (map)
150mm f/17.6 refractor by Tully 1827

A fine double star [DL Tri and SAO 75264], between the Ram and the Triangle, where it will be found by shooting a line from α Andromedæ through α Trianguli, and extending it nearly 5° beyond: it is also near the mid-distance between γ Andromedæ and γ Ceti. A 8½, and B 9, both silvery white. This object, formed by Piazzi's Nos. 38 and 39, was classed H IV 40, in 1781; no measures of position were then taken, but the distance was found to be 17".31, "pretty accurate." H. and S. found it thus:

    Pos. 208°56'  Dist. 14".35  Ep. 1821.96
       [ 212°           14".00      2019 WDS ]

which is too similar to the result given by my measures thirteen years afterwards, to confirm the retrograde motion inferred from a reduction of Piazzi's mean places for 1800, which give 211°.5 for the angle, and 16".8 as the distance.

― A Cycle of Celestial Objects Vol II, The Bedford Catalogue, William Henry Smyth, 1844

Drawings, descriptions, and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission.

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