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Re: A new game to play: scan candidates for high proper motion
- To: Undisclosed recipients: ;
- Subject: Re: A new game to play: scan candidates for high proper motion
- From: Tass Mailing List <tass@mail.alembic.net>
- Date: Tue, 08 Aug 2006 21:41:25 -0700 (PDT)
- Delivery-Date: Wed Aug 9 00:52:32 2006
Date: Tue, 08 Aug 2006 20:32:08 -0500
From: Michael Sallman <msallman@pro-ns.net>
To: Tass Mailing List <tass@mail.alembic.net>
Cc: "Undisclosed recipients: ;"@smtpout-2.iphouse.net
Subject: Re: A new game to play: scan candidates for high proper motion
Arne,
I would say that he has cross referenced it, as at the bottom of the
page are the Simbad matches within 5' of the TASS position. So maybe
it's more of a negative match thing... of the 50 stars in the group 17
matched stars with known high (or relatively high) proper motion. The
other 33 matched stars that DON'T seem to show high proper motion in the
POSS images. Why do they apparently show high motion in the TASS data?
Mike
Tass Mailing List wrote:
> Date: Tue, 08 Aug 2006 20:54:20 -0400
> From: arne <arne@aavso.org>
> To: Tass Mailing List <tass@mail.alembic.net>
> Subject: Re: A new game to play: scan candidates for high proper motion
>
> Based on M. Sallman's results, I get the impression that M. Richmond
> has not cross-identified his list of 1027 stars with the NLTT, LTT,
> LHS, NPM, etc. proper motion catalogs. Perhaps this should be done before
> everyone starts rediscovering known high proper motion stars.
>
> Almost all bright stars will show proper motion, as they tend to be
> close to the Sun. All stars brighter than about V=12 will also
> have their proper motions determined by either Tycho itself, or
> in conjunction with the AC (the Kharchenko 2.5 Million Star Catalog,
> available from VizieR).
>
> It is only the really high proper motion stars that might have gotten
> missed by other surveys. USNO-B, for example, had to set a maximum
> search box size to ensure matches were not just chance, but even there,
> they used a lot of survey reject plates, the Luyten plates, etc. to
> give short-interval motions.
>
> A good reference is Levine, S. E. 2005, AJ 130, 319
> ("Stars in the USNO-B1 Catalog with Proper Motions between 1.0 and
> 5.0 Arcseconds per Year")
> Arne
>
> Tass Mailing List wrote:
>
>>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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