[AZ-Observing] Re: At Antennas
- From: "Wayne (aka Mr. Galaxy)" <mrgalaxy@xxxxxxxx>
- To: az-observing@xxxxxxxxxxxxx
- Date: Thu, 27 Jan 2011 21:33:18 GMT
15480 Empire Rd.
Benson, AZ 85602
hm ph: 520-586-2244
You guys up in northern AZ seem to be closer to the jet stream activity. Last
night it was breezy during the day and somewhat turbulent early in the evening,
but by 10pm or so it settled down nicely.
The past week or two the seeing has been very good for the most part in the
Benson area and despite there being a bright moon in the sky I have been doing
my "Richard Harshaw" thing observing doubles, some of them closer than what I
thought could be done from my location and with my instruments.
Although I didn't get to the diffraction limit of my telescope, I was happy to
find a few doubles that were under one arcsecond separation. Trying to do close
doubles is a challenge with unguided Dobsonian mounted big reflectors, but in
my 13-inch f/6.5 I actually saw diffraction rings around stars on a few of the
nights indicating good seeing and cooperating instruments. I used my 13-inch
with 7 and 9mm eyepieces in combination with a x2 Barlow (giving 610x and 475x,
respectively) for observing the subarc stars. Most of the doubles I looked at
were in the constellation of Orion because it was so well placed at the time of
my observations.
I, of course, started off with the Trapezium in the Orion Nebula and saw six
components. Then I went to zeta Ori (Alnitak) and was surprised to see that it
was a close, unequal double. Most of the time we're so busy looking at the
nebulosities around this star in the belt of Orion that we ignore it. The best
I did in Orion were the doubles 52 Ori and 14 Ori (my first subarcsecond
split). There are any number of 1-2 arcsec stars in the area to discover for
yourself.
I used Kepple and Sanner's Night Sky Observers Guide, but I don't know for what
epoch the stars' separation is given (I think it's the year 2000 for some), so
I just estimated position angles and separations to look up later to see how
well I did. The Observers Handbook by the RASC is a good, but limited
reference. It at least gave up-to-date positional data for a few stars so that
I could gauge what I was seeing. I had the most difficulty determining the
position angle (pa) of the stars in a system since north is in a different
location for each double star and the field rotates as the stars move through.
I probably spent most of my time trying to reposition the telescope with its
small field of view, especially at high power. I understand the US Naval
Observatory has a website for the Washington Double Star (WDS) to check on
current ephemerides, but I haven't checked it out thoroughly.
I stayed up late a couple nights and ventured into Coma Berenices and Sextans
and was able to split alpha CBr and gamma Sex (both about 0.6 arcsec).
Unfortunately I couldn't stay up late enough to check out Bootes which contains
several nice very tight doubles, though I did try Izar - it was split but
bloated.
Earlier in the evening in moments of good seeing I was able to split Sirius,
but detecting the secondary is a real challenge with my standard observing
setup. I didn't try anything to modify the diffraction spikes to make detection
easier. I tried several stars that are indicated as doubles on the star charts,
but no companions were seen. I don't know if those are spectroscopic or
parallactic doubles, which I don't think should be shown as doubles in an
observing atlas. They should at least be indicated with different symbology.
It's as bad as showing radio sources which are highly interesting visually
through a telescope!
Anyway, it's been great resolving some of these challenges; there's something
compelling about it. Unfortunately, I don't have a bifilar micrometer to make
measurements, but it would be fruitless without a clockdrive anyway. It would
be fun to see if scientifically useful measurements could be made, but that
will have to wait for a decent influx of funds.
Now that I know splitting close binaries can be done here, I'm going to chart
(since I don't have setting circles) the list of challenge doubles Richard left
with us when he gave his talk at the HAC group and see how I can do with those.
It's been fun and I'm looking forward to the doubles in Bootes, but now that
the moon is leaving it's time for galaxies!
Clear skies,
Wayne (aka Mr. Galaxy)
---------- Original Message ----------
From: Richard Harshaw <rharshaw2@xxxxxxx>
To: az-observing@xxxxxxxxxxxxx
Subject: [AZ-Observing] Re: At Antennas
Date: Thu, 27 Jan 2011 08:01:35 -0700
Yeah, it was real windy here last night too. I was in BSO until about 10:30.
The whole time I was out, the wind kept flapping my black drapes like flags
on an aircraft carrier during launch.
I'll probably head out this afternoon and spend two nights. Saturday is
looking iffy sky-wise.
Dick
On Thu, Jan 27, 2011 at 12:59 AM, <stevecoe@xxxxxxxxxxxxxxxx> wrote:
> Howdy all;
>
> Joe Goss and I are at the Antennas site and it has been OK, but not great.
> The sky is clear but very "twinkly". Lots of wind and lots of star
> movement even at low power. Joe and I are hoping that it will calm down
> for the next few nights and let us get a little more observing done.
>
> I have a plan for some images to take, but I would be concerned that the
> wind would blow the camera around during the exposure.
>
> Clear skies to us all;
> Steve Coe
> --
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> send personal replies to the author, not the list.
>
>
--
Richard Harshaw
Cave Creek, AZ
--
See message header for info on list archives or unsubscribing, and please
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