开云体育

Well, I know Attilla is waiting anxiously for this, so here goes:

Session: 2001-014
Date/time: 2001-04-18 21:00 - 03:00
Location: Fred Lossing Observatory, Almonte, Ontario.
Weather: 5 (arr) dropping to -3 (dep), calm, cloud 0/10

Present: Al Seaman, Matt Weeks, Geoff Meek, and I.

Limiting magnitude and seeing: I'm still working on this. Best I can say
is that when I arrived, and when I left, I could easily see all the stars of
the UMi asterism, so the LM was better than the last time I was there (not
saying much). After about 01:00, stars started to have a bit of a halo,
indicating (I suspect) water vapour in the sky. No moon for entire session.

Instrument: G-8 SCT, also had peeks in FLO 16" Newt and Geoff's? 10" Dob.

Observations:

1) ISS: Saw pass at 21:29. Went straight overhead and winked out at about
130. No sign naked-eye of Soyuz. This was Matt's first sighting of ISS,
my 6th or 7th. It was not quite as bright as I remember it last fall, when
I say it in twilight. Does that make sense?

2) Polaris: I managed to centre Polaris this time, by setting the RA
correctly. Could not split double, though. I suspect it was because the
OTA wasn't cooled down yet. Saw clear and active tube currents when I
de-focused. Forgot to come back to this later in the session.

3) Jupiter: Just for the heck of it. Observed with 10mm EP (200x).
Pretty mushy, since OTA still not cool. Saw 3 moons, 2 close together on
one side and 1 opposite. Turns out, IO was in transit. Didn't see it, or
its shadow, though.

4) M37: Tried locating it using procedure suggested by Roland last time
out. No luck, because I couldn't get set up on the guide stars. Reverted
to old method - telrad dead-reckoning. Hit it first try! That was my first
time finding M37. Nice OC. Matt had just been looking at it in his scope,
and commented that there appeared to be a red star at the centre of M37. I
confirmed this. He also mentioned that there appeared to be dark lanes
visible in several areas of the cluster. I could see what he meant.
Switched from 32mm EP to 10mm, to have a better look, but colour and
contrast seemed less, so gave up.

5) M36: Found it as above, telrad dead-reckoning. Much less impressive!
Maybe 40 stars visible? Very sparse too. Looked with both 32mm and 10mm
EPs. Better with wider field. Estimated size to be 15 - 20' diameter.
This was my first time seeing M36, and also the first time I've tried to
find it.

6) M38: Hopped to it from M36 using the telrad scale and Eta Aurigae as
guides. First time trying for, and finding M38. Pretty unimpressive; much
like M36. Maybe 50-60 stars evident? Estimated diameter to be 25'.

7) M3: Revisited it for maybe 4th time, just to prove I could still find
it, and to take my first careful look at it. Located it with
telrad-F/S-32mm EP, then switched to 10mm EP. Centre is best observed with
averted vision. Outer stars were distinct, but nowhere near the same as in
Mike's Obsession.

8) M13: (Her) Found in no time, although pretty dark in finderscope this
time. Not as impressive as at Mike's. Using 10mm EP. Centre is bright
like a nebula, surrounded by distinct stars. Had an impression of a dark
lane running tangentially, about 3/4 of way out. Estimated diameter: 3 -
4' for core, 7 - 8' overall. This was the second time I viewed M13, and the
1st time to examine it closely. Al showed it to me in his 10" SCT using a
Nagler EP, and then again in the 16". Nice. The Nagler EP really brought
out the stars (aperture helped, I'm sure). No dark lane evident, so it must
have been my imagination in my scope.

9) M92: Al dialed in M92 on the 18" setting circles, and we viewed it with
his Nagler EP. Very pretty. I showed him how to find M92 using Roland's
procedure. Took him a while, checking it out in my scope as he went, but he
eventually succeeded. That makes two people I've helped find it now!
Diameter of core: ~3'.

10) Eskimo Neb. (UMa): Saw it in Geoff's 10" Dob. Tried to find it in
mine using telrad. No luck. Something for later.

11) M57 (Lyr) : Ring Nebula. Found with some difficulty, despite the fact
that Matt informs me he located it for me in my scope at Mike's. I don't
remember, and didn't log it. Could not find it in the finderscope. Went
straight from telrad to 10mm EP. Faint ring of about 1 - 1.5' diameter.
Best in averted vision. No detail apparent. This was the first time I've
found M57, and I found it without a guide procedure from anyone else.

12) Mars: Observed it using 10mm EP, when it was about 25-30 above
horizon. Bright. Wondered if my new 13% ND filter would have helped, but I
was getting cold and tired, so didn't try. The red colour naked-eye was not
apparent at the EP; looked more yellow-orange. As at Mike's, there was a
colour gradient across the disk, at about a 45 angle. In the NW, it
appeared yellow-white, while in the SE, it appeared more orangish, with a
tinge of turquoise-blue right at the edge of the disk. Could that be
chromatic aberration? This was with an Orion LV 10mm EP.

13) M5 (Ser): Was familiarizing myself with this part of the sky using my
planisphere when I noticed M5 marked. Decided to go for it, even though it
wasn't one of my objectives. Located it using telrad and intersection of
lines running up from Libra and across from Serpens to Virgo. Nice globular
cluster. Diameter apparent: ~4'. Bright centre. Appeared to have a
roughly triangular shape overall?

14) M4 (Sco): Near Antares. Found it with some difficulty and help from
Geoff. Globular cluster. Few stars (relatively speaking). Faint
irregularity in core seemed apparent.

As these last, rather undescriptive notes may hint, by 03:00 I was getting
tired and cold. When Geoff started packing up, I decided to do the same.
Overall, this was a very productive and fun night. 6 first-time Messier's!
Boy, was I tired when I got home, though.

--- In OAFs@y..., "Bruce McGlashan" <mcglashanb2@h...> wrote:

As at Mike's, there was a
colour gradient across the disk, at about a 45° angle. In the NW,

it

appeared yellow-white, while in the SE, it appeared more orangish,

with a

tinge of turquoise-blue right at the edge of the disk. Could that

be

chromatic aberration?

Its much more likely to have been caused by the atmosphere
rather than your scope. All objects when observed at low altitudes
tend to show it, its just easiest to see on planets. The real
proof is to rotate your scope. Atmospheric chromatic dispersion
wont rotate. It will always show a color separation up and down.
On a polar aligned scope, that might look like a 45 degree angle
depending on how your star diagonal is aligned.

by 03:00 I was getting tired and cold.

An impressive observing seesion for a weeknight.

-ad

--- In OAFs@y..., attilla.danko@s... wrote:

--- In OAFs@y..., "Bruce McGlashan" <mcglashanb2@h...> wrote:

As at Mike's, there was a
colour gradient across the disk, at about a 45 angle. In the NW,

it

appeared yellow-white, while in the SE, it appeared more orangish,

with a

tinge of turquoise-blue right at the edge of the disk. Could that

be

chromatic aberration?

Its much more likely to have been caused by the atmosphere
rather than your scope. All objects when observed at low altitudes
tend to show it, its just easiest to see on planets. The real
proof is to rotate your scope. Atmospheric chromatic dispersion
wont rotate. It will always show a color separation up and down.
On a polar aligned scope, that might look like a 45 degree angle
depending on how your star diagonal is aligned.

Thanks! I'll check this out next time.

by 03:00 I was getting tired and cold.

An impressive observing seesion for a weeknight.

Maybe not. I'm on vacation this week.

-ad

Bruce McGlashan

p.s. In case I don't talk to any of you beforehand, I hope the weather
cooperates tonight and on Saturday. I'm off to Toronto tomorrow, for my
brother's wedding Saturday, so I won't be participating in any activities
until next week.

Bruce -

I really enjoyed reading your FLO Observing Report, especially the
detailed descriptions of how you located various M objects. I felt
like I was there, targeting the red bull's eye between two stars,
changing eyepieces, estimating cluster sizes - armchair astronomy at
its best!

I, too, am a big fan of telrads. It is so satisfying to study a map
carefully, plot little triangles and lines in your head, aim the
telrad thinking "I think it's about . . . there!", looking in the
eyepiece, and - at least on lucky occasions - seeing a little smudgy
ghost of a galaxy staring back at you.

I also like to use the telrad as a preliminary step to using the
finderscope, just to make sure I'm embarking on my search from the
correct star.

BTW, you're very welcome re use of the red flashlight at previous
sessions. Glad you liked it.

Janice

Bruce McGlashan wrote:

--- In OAFs@y..., attilla.danko@s... wrote:

--- In OAFs@y..., "Bruce McGlashan" <mcglashanb2@h...> wrote:

As at Mike's, there was a
colour gradient across the disk, at about a 45 angle. In the NW,

it

appeared yellow-white, while in the SE, it appeared more orangish,

with a

tinge of turquoise-blue right at the edge of the disk. Could that

be

chromatic aberration?

Its much more likely to have been caused by the atmosphere
rather than your scope. All objects when observed at low altitudes
tend to show it, its just easiest to see on planets. The real
proof is to rotate your scope. Atmospheric chromatic dispersion
wont rotate. It will always show a color separation up and down.
On a polar aligned scope, that might look like a 45 degree angle
depending on how your star diagonal is aligned.

Thanks! I'll check this out next time.

Interesting piece of trivia. The colour caused by the atmosphere came
up a while ago on sci.astro.amateur (which I spend entirely too much
time reading - except for the authors and topics I've just kill-filed)
wrt some reviews of the Takahashi Sky 90. Basically the atmosphere is
just acting like a big prism. The neat thing that someone brought up is
that there is apparently an eyepiece that someone (British I think)
where one of the lenses can be moved around so that it acts like a prism
in the opposite direction. And there was some other widget where an
actual prism got introduced in the light path to again cancel the
atmospheric effects. Personally I would be skeptical as to the final
image quality you could get - or maybe I just misinterpreted what was
being described.

by 03:00 I was getting tired and cold.

An impressive observing seesion for a weeknight.

Maybe not. I'm on vacation this week.

Ah-hah! (that's cheating!!) Lucky you.

Actually, Saturday morning I got home from Mike's and after minimal
unpacking and walking the dog (short walk) I got up to the bedroom at 4
to find my wife reading a book. Apparently she woke up at 2 and I
wasn't home and then spent her time waiting for the call from the
police... she's now threatening to get me a cell phone for my
birthday. (She and I both consider cell phones to be inherently evil
:-) Anyone have any recommendations on phones/plans for very infrequent
use?

-ad

Bruce McGlashan

p.s. In case I don't talk to any of you beforehand, I hope the
weather
cooperates tonight and on Saturday. I'm off to Toronto tomorrow, for
my
brother's wedding Saturday, so I won't be participating in any
activities
until next week.

There used to be phones which were relatively low cost to buy, no monthly
fees, but pay rather heavily by the minute when you use it. Seems ideal.
I've sometimes considered something along those lines (especially after
nearly having my car not start at 05:00 at -32C in January at FLO). I keep
hoping my employer will think I need one for work (not likely).

Rick

--- In OAFs@y..., Rob Robotham <rob.robotham@a...> wrote:

Bruce McGlashan wrote:

... [snip] ...

by 03:00 I was getting tired and cold.

An impressive observing seesion for a weeknight.

Maybe not. I'm on vacation this week.

Ah-hah! (that's cheating!!) Lucky you.

Actually, Saturday morning I got home from Mike's and after minimal
unpacking and walking the dog (short walk) I got up to the bedroom at 4
to find my wife reading a book. Apparently she woke up at 2 and I
wasn't home and then spent her time waiting for the call from the
police... she's now threatening to get me a cell phone for my
birthday.

LOL! Roland and Attilla will attest to the fact that my wife went through
the same thing last week. We were sitting in Denny's having 'breakfast' at
about 01:30 (as I recall) when my cellphone went off. My wife Jan was
starting to worry. Since then, she's given up worrying and gone to bed. I
think she decided that if I've got a cellphone, I'll call if I'm in trouble,
otherwise she'll just get an earful of excited astro-babble if she calls.

(She and I both consider cell phones to be inherently evil :-)
Anyone have any recommendations on phones/plans for very infrequent
use?

As for a phone/plan to recommend, the night that Roland, Attilla and I were
at FLO, we had three Nokia phones there on three services: Bell, Cantel and
Fido. As I recall, my Bell phone had the worst problems, Attilla's FIDO was
marginal, and Roland's Cantel service was the most reliable, although he
seemed to have to repeat himself a lot (without actually dropping service).
I have also taken my wife's Nokia/Cantel phone to FLO, and I think it did
OK, given the battery draw I noted when I got home (it takes more battery
juice when it drops into analog or into service-search mode). Maybe you
should poll the others at your favorite observing sites, since that's what
will count.

I think the cellphone is a good idea. It gives both of you peace of mind,
and your wife will still feel she can get in touch with you if necessary.
As for cellphones being 'evil', I understand your POV; my wife and I
resisted them for a long time too. There are still lots of times and places
where they are definitely evil, but IMHO an observing site is not
necessarily one of them. If you sit there yacking all the time, those
around you will likely be peeved, but I think most people would understand
the odd call from the SO.

Funny thing - I gave my wife her cellphone as a gift, after months of hints
(from her). For the first three months, she didn't register a >single<
call, and I had to nag her to turn it on so I could get in touch with her!
Then, like a switch being flicked, she started using the phone. She's
definitely not one of those annoying yackers you encounter on the bus or in
the malls, but she is now using it the way it should be used. Be
forewarned - you may go through a similar adaptation period.

Bruce McGlashan

Bruce McGlashan wrote:

Session: 2001-014
Date/time: 2001-04-18 21:00 - 03:00
Location: Fred Lossing Observatory, Almonte, Ontario.
Weather: 5° (arr) dropping to -3° (dep), calm, cloud 0/10

Present: Al Seaman, Matt Weeks, Geoff Meek, and I.
[...etc...]

A great report Bruce.

As these last, rather undescriptive notes may hint, by 03:00 I was getting
tired and cold. When Geoff started packing up, I decided to do the same.
Overall, this was a very productive and fun night. 6 first-time Messier's!
Boy, was I tired when I got home, though.

Boy, you are a bear for punishment - I was getting pretty pooped by 1:30
when I left, and since I had a fair bit of running around to do to-day
didn't want to make it later. Glad to hear that the session at FLO went so
well for you. I also enjoyed the evening and the company of a good group.

Cheers - Al