Re: A new game to play: scan candidates for high proper motion

[Tass Mailing List <tass@mail.alembic.net>]

Date: Tue, 08 Aug 2006 18:24:52 -0500
From: Michael Sallman <msallman@pro-ns.net>
To: Tass Mailing List <tass@mail.alembic.net>
Subject: Re: A new game to play: scan candidates for high proper motion

Group 12 stars that appear to move significantly:

481 	= HD 212141 - moves slightly in the POSS images, proper motion per
Simbad is 138.89 mas/yr
208699 	= LHS 3828
250303 	= LHS 6421
2595   	= G 79-29
4205	= HD 72053 - moves slightly in the POSS images, proper motion per
Simbad is -128.85 mas/yr
107241	= HD 100362 - moves slightly in the POSS images, proper motion
per Simbad is -115.22 mas/yr
106231	= HD 109180 - moves slightly in the POSS images, proper motion
per Simbad is -74.00 mas/yr
119136	= HD 129414 - seems to move slightly in the POSS images, proper
motion per Simbad is -11.00 mas/yr
179772	= LTT 15462
180244	- close pair of stars
203618	= HD 181437 - moves slightly in the POSS images, proper motion
per Simbad is -71.50 mas/yr
541	= LTT 16548
7856	= HD 449 - moves slightly in the POSS images, proper motion per
Simbad is 124.98 mas/yr
74282	= LTT 10467
53651 	= BD+09 210 - moves slightly in the POSS images, proper motion
per Simbad is (37.30 -55.10) mas/yr
40575	= HD 14068 - moves slightly in the POSS images, proper motion per
Simbad is (68.92 -42.02) mas/yr
40956	= HD 14254 - moves slightly in the POSS images, proper motion per
Simbad is 96.27 mas/yr
74806	= G 79-65


Mike

Tass Mailing List wrote:
> Date: Mon, 7 Aug 2006 07:59:56 -0400
> From: Michael Richmond <richmond@stupendous.cis.rit.edu>
> To: tass@tass-survey.org
> Subject: A new game to play: scan candidates for high proper motion
>
>
>   In the course of putting together the "patches" dataset,
> I realized that it might be used to look for stars with
> high proper motion (that is, movement across the sky relative
> to other stars).  There have been many other surveys designed
> specifically to find stars with high proper motion, so I
> don't really expect to find many (any?) new stars in this
> category .... but you never know.
>
>   One area in which TASS may have some advantage is in the
> case of _very_ large proper motion, of >= 2 arcsec per year.
> In some cases, the TASS cameras make many measurements of
> the same field within a single year, so that such stars
> will show clear movement, yet still easily be recognized
> as a single source.  Some other proper motion surveys have
> used two plates taken a decade or so part, during which such
> swiftly moving stars might move so far that they might
> not be recognized as the same object.
>
>   Anyway, here's what I did:
>
>          - fit each star's position in RA versus time with
>                 a straight line; it yields proper motion in RA
>                 (arcsec per year), plus a two-sigma estimate of the
>                 uncertainty in the motion
>
>          - ditto Dec: proper motion in Dec (arcsec per year),
>                 plus two-sigma uncertainty in motion
>
>          - pick stars which satisfy
>
>               a.  at least 10 measurements
>               b.  motion in at least one direction exceeds 5*2-sigma
>
>   There were 1027 such candidates.  I wrote a Perl script which
> gathered a bunch of information on each candidate, made some
> plots showing all positions of the candidate, and motion as a function
> of time, cutouts at the candidate's position from
>
>         POSS I        (roughly 1950s)
>         POSS II       (roughly late 1980s)
>         2MASS         (roughly 2000)
>
> plus a search for information at the position in SIMBAD.  All
> this information is gathered together on one web page per candidate.
> One can scan the page in just a few seconds -- I recommend going
> to the end, where the cutouts of the sky surveys make it VERY
> easy to judge whether motion is real or not.
>
>   An example of a candidate with spurious proper motion is
>
>     http://spiff.rit.edu/tass/proper_motion/cand_294362/measure_294362.html
>
>   An example of a candidate with TRUE proper motion -- alas, already
> known to science -- is
>
>     http://spiff.rit.edu/tass/proper_motion/cand_296359/measure_296359.html
>
>
>
>   Here's what I ask of interested readers: could you please help me
> to scan through this set of over 1000 stars and find those with
> REAL proper motion?  Here's what to do:
>
>      - go to the index page
>
>            http://spiff.rit.edu/tass/proper_motion/group_cand_index.html
>
>        where I have broken the 1027 stars into groups of 50.
>        Pick one group.
>
>      - click on the link for that group to go to its first candidate.
>
>      - scan the information, decide if the candidate is real or not.
>        If it is really moving, note its number
>
>      - use the links at top or bottom of the page to go to the
>        next candidate in the group
>
>      - when you have finished 50 objects (it may help you to write down
>        the index of the first candidate in the NEXT group, in case
>        you lose count of your fifty), send an E-mail to the TASS
>        mailing list with a summary of your results
>
>   It's too many for me to do all by myself.  Help!
>
>
>                                             Michael
>
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