Anyone measuring 70 Ophiuchi?

Hi,

I started tracking this nearby binary system back in summer 2004, and
was intending to repeat my observations every other year in the hope of
seeing some movement in my *limited* 8" Newt. I'd totally forgotten
that I managed to do an article on it back then:

http://www.astroscience.org/abdul-ahad/astrometry.htm

Can't wait for summer to roll in so I could repeat the exercise and see
if anything's changed :-)

Is anyone here already on the ball with this?

cheers,
AA
http://www.publishedauthors.net/aa_spaceagent/

"Abdul Ahad" wrote in message
oups.com...
Hi,

I started tracking this nearby binary system back in summer 2004, and
was intending to repeat my observations every other year in the hope of
seeing some movement in my *limited* 8" Newt. I'd totally forgotten
that I managed to do an article on it back then:

http://www.astroscience.org/abdul-ahad/astrometry.htm

Can't wait for summer to roll in so I could repeat the exercise and see
if anything's changed :-)

Is anyone here already on the ball with this?

cheers,
AA
http://www.publishedauthors.net/aa_spaceagent/



Good luck with o****ee

Paul Schlyter wrote:
In article .com,

It would have been easier to do this sone 20 years ago. when 70 Oph passed
through periastron.

In the 1980's I made some drawings of 70 Oph using a 4-inch refractor.
After only a few years the motion was easily seen visually - 70 Oph had
then moved through some 90 degrees in PA.

Now its movement is much slower.

True. Though having a telescope back in the 1980s that could resolve 70
Oph was something of a "dream" for me...

I would be content seeing just some movement either in separation or
PA, though the latter will now be tiny. The pair look set to continue
to widen through 2020 when apastron will be reached, with a whopping
max. separation of some 7.5 arc-secs.

The other component I'm tracking with this star is its proper motion.
With a near one full arc-second per year, it should become obvious in
just a few years.

AA
http://www.publishedauthors.net/aa_spaceagent/

Paul Schlyter wrote:

The best candidate is Alfa Centauri, but perhaps you don't live far enough
south to be able to see it.

I wish! Perfect candidate for my amateur scope. [It's the target system
in my new sci-fi novel 'First Ark to Alpha Centauri' :-) ]

Other candidates could be Xi Ursae Majors and Gamma Virginis. The latter
is very near perihelion right now, and the separation is so small that
you'll see it as a single star. But do observe it every year during the
next decade, and see that "single" star split in two!

Yeah, Gamma Virginis is another pair I'm keen on following. I checked
the ephemeris predictions from the US Naval Observatory's sixth orbit
catalog:

http://ad.usno.navy.mil/wds/orb6/orb6ephem.html

The PA (degrees) and separations (arc-secs) are going to be as
follows:-

2005: 168.1, 0.381
2006: 85.8, 0.439
2007: 50.5, 0.726
2008: 35.2, 0.997
2009: 26.2, 1.238

Luckily for me, the two stars are of near-equal brightnesses so I think
in the next couple of years I'll start to see Gamma Vir as a 'double'
for the first time...

AA
http://www.publishedauthors.net/aa_spaceagent/