Re: (SNES) No Luck with Asteroid 2002 NY 40

["Les Lytton" <Starman@SAMnet.net>]

Ernest R. Evans said:


After downloading a detailed finder chart down to 9th mag from S&T's
website, I set out last night to track it down with my 6" f/4 from 10:00 to
11:30.  Using the chart, I zeroed in ( hopped/offset) to the expected field
directly south of gamma Lyrae at 10:10.  Checked field's stars for movement,
could not spot asteroid.  At 22:30 I hopped from beta Lyrae south to a star
just north of the expected asteroid trajectory (field certain) and eased
south in declination slightly to the asteroid's path.  Again, asteroid not
sighted within 10' of expected time or place.  I repeated this procedure of
hopping to stars very near the asteroid's expected place along its path in
advance and carefully examining the fields (fields certain) three more times
without success.  (SIGH!)

Hope someone had better luck -- was the asteroid close to its calculated
time and place, or am I just an incompetent buffoon?!!!

Ernie

PS  I can take public humility addressed to buffoon!


************************************************************

Hi Ernie and all,

I gave it an attempt to try capturing NY40 on emulsion film that Sunday
night.  My plan was to capture a visual record not only of its passage
across the sky, but also its drop in brightness as it turned it unlit back
side more and more toward us.

I'm not sure what went wrong for you.  I was able to initially pick it up in
tripod mounted 11x80 binocs at about 9:30 from my relatively light polluted
back yard.  This was accomplished, thanks in no small measure, by using a
finder chart graciously provided by Dave Bartolini.  The tiny piece of rock
was extremely difficult to see through all the clouds and haze that were
present (add to that the night glow from downtown Springfield, MA just 5
miles to my NE).  That I was able to see it in the binocs at all was a major
achievement under the circumstances.

When I shifted to my C14 equipped with my lowest power eyepiece (55mm
Plossl), providing not quite a 1/2 degree fov at 78X, I started by training
the scope to NY40's current plotted position for 9:45 PM as per a NASA
generated ephemeris.  I was able to detect the asteroid's movement within 10
to 15 seconds.  It appeared quite bright for me, and was very obviously
moving against the background stars, like a bright satellite.

Ernie, could your problem have been attempting to locate NY40 by starting
with too high a power, and thusly too restricted a fov?  Other than that,
I'm not sure what the problem you encountered might have been.  Because you
stated you also positioned your instrument from a reference chart, did you
do an accurate check on your polar alignment before you began?  Could your
mount possibly not have been level?  Sorry I can't offer more, but I would
need more details on how you went about your attempt.

Here's a belated report on my evening's attempts to photograph NY40, along
with some of my own thoughts to compare with Dave Bartolini's earlier post.
My comments are marked with ***  Unfortunately, as Dave said, New England
just doesn't seem to like us astro-types:

**********

The night of Sunday, Aug 17th was a mixture of frustrations, I'm sorry to
say.  As dusk approached, my expectations for success were soaring, but by
9:00, it had become very obvious that a successful long-term photo session
was quickly fading away to impossible.  The clouds just became thicker and
thicker.  Even the holes between them were extremely haze occluded.

I had achieved what I felt to be a good polar alignment and had the camera
attached to the scope by 9:30, but even through the holes, the best visual
magnitude I was able to detect was only about 4.5.  To help initially
identify NY40, I used my 11x80 binoculars mounted on a tripod.  It took
almost 15 minutes before I was certain of NY40's position.  Because of the
sky conditions, even the two 2nd magnitude stars that bracket M57 would fade
completely away from view in the binoculars, then return after about 5
minutes or so.  This made detecting NY40's movement all but impossible.  As
it turned out, at the moments of best clarity, I was able to see NY40 only
with averted vision.  I do think that if it were a good night, NY40 would
have been bright enough to have been seen with direct vision at its
brightest (mag 9.8) from my yard with the 11x80s.  I also do feel that
anyone attempting to use binocs w/50mm objectives would have needed a much
darker site than my yard.

I finally picked up NY40 in the scope (had to unmount the camera) with my
55mm Plossl at about 10 minutes to 10:00.  My plan was to take the first
picture of the night at 10:00.  I let the asteroid drift across the fov to
ensure I had its line of travel down, and the time it took to transit the
fov, then repositioned the scope one fov ahead of it.  I quickly remounted
the camera and was ready to release the shutter cable for the first shot,
when I realized a massive cloud had moved in and totally obliterated that
part of the sky.

To make a long sad story of futility short, I was unable to follow through
with my original plan, and wound up with about 7 individual shots from 10:00
until about 1:30, when I finally gave up and went to bed.

Dave Bartolini wrote:

Here are a couple of things that I took away from the NY40 search, apart
from the fact that NE weather is not astro-friendly. Given that there was a
similar asteroid a year ago (1998 WT24), I expect that the LINEAR program
will find more of these near misses in the not to distant future for
interested observers and imagers to try again.

1) These NEO's are telescopic and/or photographic objects. They don't really
move fast enough to be observable with binoculars unless the binocs are
mounted and you have a really comfortable seat. They probably have to be
really close and/or really big to be fast enough and/or bright enough to be
distinguishable from stars with binoculars.

*** I agree wholeheartedly.  Even at a truly dark site, NY40 would have been
an extremely challenging object in solidly mounted 7x50s, and completely
impossible to detect hand held.  In comparison, Jupiter's four Galilean
moons are roughly four times brighter than NY40 was at its brightest.  How
many can truthfully claim to have seen them in hand held 7x50s?  But they
stand out boldly if the binocs are securely mounted.  I am sure that anyone
who went out with just a pair of hand held binocs to see NY40 gave up the
effort after a few minutes of disappointment.

2) The finder chart that I posted early last week is good for imagers, but
not optimal for visual hunters. For the next NEO, I'll post more detailed
charts  to aid in visual observations.

*** I disagree with you, Dave.  It was this finder chart that allowed me to
identify NY40 with the 11x80s.  It took probably 3 times longer than it
would have if the sky had been clear, but the chart allowed me to identify
the tiny speck of light which was the only object that changed its position
in reference to the stars on the chart.  The only time I used the ephemeris
was to initially aim the C14 at NY40's 2145 position.  From that point on,
all else was done referencing the finder chart.  I would like to reiterate
that the finder chart would be functionless for anyone who was trying to
spot NY40 with hand held binocs.

3) With a detailed chart in hand, the best way to detect the asteroid is to
park yourself on a field of stars a couple of minutes ahead of the path of
the asteroid, then wait for it to pass through. The perfect star field would
have a couple of bright stars in a line that is perpendicular to the path of
the asteroid.

***  This is a great idea, but my experience was a little different.  Anyone
with a 6" or larger instrument should have been able to quickly acquire NY40
using their lowest power eyepiece for the largest fov in conjunction with
the finder chart.  It is essential to know where the asteroid would be at
any particular moment in relation to close-by stars.  Starting the
identification process by first selecting a specific plotted position on the
chart, then pointing the scope at that spot, the asteroid's brightness and
speed (both magnified by the scope) should be detected in a matter of just a
minute or less.  In my scope at 78x with a fov of just less than 1/2 degree,
I spotted NY40 for the first time within about 15 seconds or so.  It had the
appearance of a very bright satellite, with a steady motion across the fov
that was fast enough at that magnification to be almost instantly spotted.

4) I found that an eyepiece/telescope combo which yielded roughly a 1 degree
true field of view was a very good setup. My particular setup (with a 38mm
Rini eyepiece) yielded about 66x magnification.

*** Again, I agree with you completely.  The larger the field of view, the
slower NY40's apparent motion would have been, thus harder to detect.  In
the 11x80s with a 4 degree fov, I had to continuously shift from the
binoculars to the chart, to the binocs, back to the chart, until I was
finally able to realize one small object at the limits of vision was
actually shifting against the background.  It's movement was not detectable
by steadily gazing at it.

5) This was a very enjoyable object to observe. Even my kids got a big kick
out of watching the object slowly move across the stars. I was actually a
little nervous about how interesting it would be to observe visually. I have
observed a more typical asteroid once (Ceres, I believe), and I can't say
that I plan on spending any energy looking for another asteroid. Personally,
I also lump Pluto and quasars into the category of boring visual objects
(obviously, others may differ). I can imagine that asteroids and Pluto would
be interesting objects for imagers. Images taken across several nights make
for interesting animated GIFs (hint, hint).

*** Over the years, I have photographed several asteroids, and I must admit
that unless you have a definite interest in asteroids, they are a relatively
humdrum object to view.  The fun is positive identification, as is also true
of Pluto.  They can present quite a challenge, and in more than one
instance, can take several nights in succession to positively identify.  All
in all, Sunday night was a lot of work, mostly in vain, but at the same
time, it was a lot of fun in the attempt.  As I've said before, if ya don't
try, ya don't get.

Regards,
Dave B.

p.s. Les - were you able to catch anything?

*** Mostly a lot of high altitude condensed water vapor

*********************

I don't know if any of this helps you, or just raises your frustration
level, Ernie.  I do hope there is something in all this that may offer some
helpful hints or suggestions that one of our readers can use for the next
Near Earth Object that happens by.

Respectfully,
Les Lytton
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