Thursday, August 11, 2016

a couple more stars

Observed last night with the 8-inch.  I showed my nephew Andrew how to use the scope and he had a look at the moon, and was suitably impressed.  I think he will want to see more.

I tracked down Ross 154 again, but I did not notice much change in brightness; if anything it was a little fainter.

R Aquilae was a pretty orange in the finder and still nicer in the eyepiece at 67x, brightest in a dense field.  This variable has another big jump in magnitude shift, from 5 to 12.  It's period is speeding up by a regular pace of 0.4 days per cycle.  Its period was 300 days when first observed in 1856 but is now 270 days.  "Something" must be going on in the star to make it so.

I should add, that while star hopping to R Aquilae I had a look at what were marked in the Pocket Sky Atlas as double stars, but without their designation (being too tight or with too large a magnitude difference to be seen in smaller scopes).  There was one pair which I could squeeze in my 67x 1.3 degree field, and it was a lovely colorful "double double."  One had a blue A and a 2x fainter orange B -- usually it is the other way around -- cleanly split.  The other was of similar magnitudes but more blue-white.  Looking at the CDSA today I see they are STF 2446 & STF 2449.  STF 2446 is 9.5" separation and 6.97 vs 8.88; it has a C component 35" separated from A I did not notice.  STF 2449 is 8" separated and 7.2 vs 7.72.  It was a beautiful sight in the rich field.

61 Cygni was a bright & widely separated pair of orange stars.  They were above my roof at the time and fuzzed out with heat currents, settling to nice buttons for only a couple seconds out of ten.  Giuseppe Piazzi determined the pair's large proper motion in 1804, so it was nicknamed "Piazzi's Flying Star" -- as if it was part of a circus.  It's a little over 11 light years away.

No comments:

Post a Comment