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Re: [vsx-dis] MISAO

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  • arne
    ... That will be a valued contribution to the community. I hope that you will also consider performing some followup observations of your own - it would be
    Message 1 of 13 , Sep 1, 2006
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      martin_piers_nicholson wrote:
      > >
      > > In the case of MISAO, it is a catalog of 1340 objects, something
      > impossible
      > > to check on a one-by-one basis. (Note: it includes variables either
      > > discovered by Martin, or on some of his images.)
      >
      > I would not want colleagues to feel that I had any significant role in
      > the vast amount of work done by the MISAO team. I think the total of
      > my contribution is two variables found in one batch of images I
      > supplied. The overwhelming majority of the new variables are down to
      > Ken-ichi Kadota and Nobuo Ohkura.
      >
      > http://www.aerith.net/misao/offer/list.html
      > <http://www.aerith.net/misao/offer/list.html>
      >
      > I will work through their list "as and when".
      >
      That will be a valued contribution to the community.
      I hope that you will also consider performing some followup
      observations of your own - it would be good to see your backyard
      observatory contributing data again.

      One of my real concerns are the papers either by various surveys
      or by data miners of those surveys. The refereeing process is supposed
      to catch the majority of errors in papers, but when looking at a large
      list of objects, this process can fail.

      For example, I just reviewed a paper from a GRB group that had found
      over a thousand variables in their images. Looking at the data, I would
      agree - these are variables. However, they spent half of their paper
      describing their automated method of deriving periods and classification,
      and when examining the table based on these facts, it was very obvious
      to me that the automated process was not working. Would another reviewer
      have caught this? We've rejected a couple of lists for VSX because
      inspection by the team made it clear that the false-positive rate was
      too high; some of these were refereed publications. Surveys represent
      a real challenge to proper and timely refereeing.
      Arne
    • martin_piers_nicholson
      I have looked at the first 10 entires in the MISAO database of new variable stars http://www.aerith.net/misao/data/misv.cgi?en0100 Using VSX seems to show
      Message 2 of 13 , Sep 1, 2006
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        I have looked at the first 10 entires in the MISAO database of "new
        variable stars"

        http://www.aerith.net/misao/data/misv.cgi?en0100

        Using VSX seems to show that 8 are known GCVS variables
        (#1,2,3,4,5,6,8 and 10)

        #7 only has seven data points on three days does also link to NSVS
        #9 only has six data points on three days but does also link to NSVS

        I don't really see that the MISAO data adds much to the debate.
        Should these just appear in VSX named as GCVS or NSVS variables
        rather than MISAO variables?

        As people probably know I do most of my observing using remote
        facilities in New Mexico. It would be simple to write a script that
        would take weekly V band images of say 50 NSVS variables (or indeed
        50 MISAO variables) every week for a few months.

        BUT - would this be a sensible use of observing time? Would these go
        into VSX as Nicholson 1 to Nicholson 50 <grin>?
      • arne
        ... If you look at the references, you will see that these are known GCVS variables because they were discovered by MISAO and published in IBVS. ... That is
        Message 3 of 13 , Sep 1, 2006
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          martin_piers_nicholson wrote:
          >
          >
          > I have looked at the first 10 entires in the MISAO database of "new
          > variable stars"
          >
          > http://www.aerith.net/misao/data/misv.cgi?en0100
          > <http://www.aerith.net/misao/data/misv.cgi?en0100>
          >
          > Using VSX seems to show that 8 are known GCVS variables
          > (#1,2,3,4,5,6,8 and 10)
          >
          If you look at the references, you will see that these are "known
          GCVS variables" because they were discovered by MISAO and published
          in IBVS.

          > #7 only has seven data points on three days does also link to NSVS
          > #9 only has six data points on three days but does also link to NSVS
          >
          > I don't really see that the MISAO data adds much to the debate.
          > Should these just appear in VSX named as GCVS or NSVS variables
          > rather than MISAO variables?
          >
          That is how they appear. Right now, VSX lists all records from all
          catalogs, so you will get multiple hits from stars that appear in
          more than one catalog. Eventually there will be a "primary record",
          where the best information from each catalog is brought together.

          > As people probably know I do most of my observing using remote
          > facilities in New Mexico. It would be simple to write a script that
          > would take weekly V band images of say 50 NSVS variables (or indeed
          > 50 MISAO variables) every week for a few months.
          >
          > BUT - would this be a sensible use of observing time? Would these go
          > into VSX as Nicholson 1 to Nicholson 50 <grin>?
          >
          They would be entered as VSX Jhhmmss.s+ddmmss
          If you published them elsewhere, then there would be a cross-id to
          Nicholson xx if that is how you listed them in the other paper, or
          to NSVS xxxx if that is how they are indexed. There is very little
          personal glory in discovering or studying variable stars; as opposed
          to "minor planet" (parentheses mine, based on the latest IAU meeting)
          studies, where the discoverer can name the body, very few stars are
          known by an individuals' name.

          What is a sensible use of observing time depends on your personal
          opinion, not anyone elses. Likewise, whether you use the nice system
          in your backyard, or RAS, is your choice. I'm just pushing you to
          restart your Daventry system too. :)
          Arne
        • ncam1999
          ... The simplest of investigations reveals MisV0001 is in the GCVS primarily because it was published in an IBVS by MISAO and the GCVS picked it up later and
          Message 4 of 13 , Sep 1, 2006
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            --- In vsx-dis@yahoogroups.com, "martin_piers_nicholson"
            <martin_piers_nicholson@...> wrote:
            >
            > I have looked at the first 10 entires in the MISAO database of "new
            > variable stars"
            >
            > http://www.aerith.net/misao/data/misv.cgi?en0100
            >
            > Using VSX seems to show that 8 are known GCVS variables
            > (#1,2,3,4,5,6,8 and 10)
            >
            > #7 only has seven data points on three days does also link to NSVS
            > #9 only has six data points on three days but does also link to NSVS
            >
            > I don't really see that the MISAO data adds much to the debate.
            > Should these just appear in VSX named as GCVS or NSVS variables
            > rather than MISAO variables?

            The simplest of investigations reveals MisV0001 is in the GCVS
            primarily because it was published in an IBVS by MISAO and the GCVS
            picked it up later and formally named it, as has happened with many a
            MISAO variable

            http://www.sai.msu.su/groups/cluster/gcvs/cgi-bin/search.cgi?search=V4652+Sgr

            In this primary instance the Mira star was found from images of the
            field of the adjacent suspected cataclysmic variable V4334 Sgr via
            using PIXY SYSTEM (1) on donated images for that field.

            The GCVS reference to the study of MisV0002 is again to an IBVS by
            Yoshida et al on MISAO variables.

            VSX also echoes this information. Probably same for t'others, I can't
            be bothered to look.

            MISAO variables predate NSVS red variables in many instances, memory
            tells me up to MisV0500 were published in IBVSs, although in what form
            I remember not, and further that these are subsequently in SIMBAD, so
            the NSVS team should have found them via cross checking. In fact the
            NSVS team did not even fully cross check against the GCVS and NSV as
            at that time said catalogues were only up to date in the SAI ftp
            archive and not integrated into SIMBAD, which had a woefully out of
            date copy. MisV often came afore subsequent published NSVS J, in
            other words, and just as often the NSVS solution is no more accurate
            and many of their long period variable periodicities are between
            farcical and very bad indeed.

            The date is likely around 2003 when which survey has priority probably
            swaps, last I was actively taking note of MISAO stuff and doing cross
            indexing work therefor up to around the MisV1200s, MisV1147 and the
            potential Nova Cephei 2001 = V0709 Cephei which I think = MisV1181 was
            about the last ones I remember. There was no NSVS data to play with
            at that time. Amateurs using visual techniques provided a lot of the
            full lightcurve for the semilegendary MisV1147, plus some allsky CCD
            several passband photometry from folk like Ondrej Pejcha. It was
            quite a little international get together on the quiet was that one.


            It is within the context of these matters that VSX can do work if folk
            experienced in such work are willing to cross correlate multiple
            entries for single objects, show the connection with reference to
            evidence, literature based or new observation based, and tighten up
            the reportage system of the database. That is what it is about. VSX
            makes the MISAO and GCVS and NSVS data available for the tidying up of
            the case of what the true situation is re the MISAO _discoveries_.

            As is, the MISAO list was imported en masse and therefore duplicates
            other entries, as many were published by MISAO, or noted to vsnet
            lists as was, and subsequently were formally adopted into the GCVS,
            which too lives in VSX.

            I'll repeat that a third time. MisVnnnn objects are often in GCVS
            because they were discovered as new by MISAOchan, checked against then
            current catalogues for newness by her alter ego Pixy Misa, and double
            checked for knownness by Kato Taichi and independently for some by
            John Greaves, although neither were formal "MISAO members".

            The NSVS database permits folk to solve such objects if they so wish,
            indeed Yoshida Seiichi himself typed and periodified several long
            known red MISAO objects using the extra data thereby made available,
            sometimes in tandem with new CCD observations by Japanese observers.

            Solution is the emphasis. The current situation reminds me that I
            advised strongly against full MISAO list import into VSX as there are
            _some_ gray area objects whilst the more certain objects are fully
            published in IBVSs (sadly IBVS data still ain't in VSX for some
            unfathomable reason) and/or already integrated into GCVS and later
            namelists. I took the view that misinterpretations re VSX submission
            could ensue based on one or two, and only a handful mind you, of cases
            carefully picked out of MISAO for agenda based illustration by those
            desirous of so doing.

            A list, no matter of what longevity, that contains some objects only
            appearing in that list on a webpage being imported into VSX could
            potentially be an unfortunate precedent, was another view I took.

            However, Seiichi is a devoted and rigorous individual, and took every
            effort to ensure his findings were new afore calling them as such.

            Remember again that the vast majority of the MisV objects appeared
            afore the current surveys and lists began to make their data public.

            > As people probably know I do most of my observing using remote
            > facilities in New Mexico. It would be simple to write a script that
            > would take weekly V band images of say 50 NSVS variables (or indeed
            > 50 MISAO variables) every week for a few months.
            >
            > BUT - would this be a sensible use of observing time? Would these go
            > into VSX as Nicholson 1 to Nicholson 50 <grin>?

            Why not Nicholson 1 to twenty million? Yes, they'd likely go into VSX
            as Nicholson 1 to 20,000,000 provided they were shown variable, shown
            truly to be new and/or shown to be properly and fully analysed and
            solved if their existance in other surveys, such as ASAS3 and NSVS,
            was under a false analysis/variability typing, as perforce they would
            be new solutions for either known or new objects. However, in the
            case of preknown but incorrectly classed objects a note should be made
            of their preknownness. If only for bibliographic reference... ...the
            old paper trail, don'tja know.

            The nature of the MISAO system is somewhat historical, it preceded the
            current datamineable (more properly, datatrawlable) surveys and was
            based on processing of donated CCD observations taken by amateurs.

            It was set up to find new asteroids by happenstance in spare images,
            something soon made irrelevant by LINEAR, and they hoped one day to
            find a nova or two, and they more or less did find one in the end.

            Whether such a scheme is strictly relevant in the modern age is
            unclear.

            A system likely more relevant to the current way of things is likely
            Vello Tabur's survey of the southern sky with a simple system,
            something he unfortunately never wrote up, coz it were impressive, and
            it found truly new variables, and solved their nature, and not all of
            those were found or included in subsequent ASAS3 releases either.

            John
          • Sebastian Otero
            ... Actually if the observations are for Misao (or any other known) variables they will enter VSX as revisions of the already existing stars so if they already
            Message 5 of 13 , Sep 1, 2006
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              >> BUT - would this be a sensible use of observing time? Would these go
              >> into VSX as Nicholson 1 to Nicholson 50 <grin>?
              >>
              > They would be entered as VSX Jhhmmss.s+ddmmss
              > If you published them elsewhere, then there would be a cross-id to
              > Nicholson xx if that is how you listed them in the other paper, or
              > to NSVS xxxx if that is how they are indexed.

              Actually if the observations are for Misao (or any other known) variables
              they will enter VSX as revisions of the already existing stars so if they
              already have a designation I don't see why a new name should be added just
              for personal glory satisfaction...
              If every variable star researcher had that purpose in mind when it is
              analysing a new or unsolved variable, the nomenclature would be chaotic.

              Cheers,
              Sebastian.
            • martin_piers_nicholson
              As a way to greatly speed the process. Ask the experts to generate a list of the MISAO variables not currently linked to a GCVS entry. Better still do this
              Message 6 of 13 , Sep 2, 2006
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                As a way to greatly speed the process.

                Ask the experts to generate a list of the MISAO variables not
                currently linked to a GCVS entry.

                Better still do this concentrating on those south of -30.

                You will find most, if not all, of these are very questionable.


                MISAO 50-100 but not in GCVS

                Very questionable
                52
                56
                59
                64
                77
                78
                79
                80
                83
                89
                97
                98

                Questionable
                58
                68
                90
                94
                96
              • Arne Henden
                Obviously, I m a little confused here. For example, #52 may have few data points, but it has nearly 2 magnitudes variation, and the images are pretty clear as
                Message 7 of 13 , Sep 2, 2006
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                  Obviously, I'm a little confused here. For example, #52 may have few
                  data points,
                  but it has nearly 2 magnitudes variation, and the images are pretty clear as to
                  which star is variable and by how much. They are even from the same observer.
                  Are you saying this is not a variable? Or are you saying that you
                  want a minimum
                  amount of information, such as a complete light curve and period
                  analysis, before
                  any star is considered variable? It certainly meets your amplitude > 2-3 sigma
                  criteria. So what do you mean by very questionable? I'm not debating with you,
                  just trying to understand your concern. 64 is similar, and is linked
                  to V1174 Sco.
                  I didn't look further into your list.
                  Arne

                  On 9/2/06, martin_piers_nicholson <martin_piers_nicholson@...> wrote:
                  > As a way to greatly speed the process.
                  >
                  > Ask the experts to generate a list of the MISAO variables not
                  > currently linked to a GCVS entry.
                  >
                  > Better still do this concentrating on those south of -30.
                  >
                  > You will find most, if not all, of these are very questionable.
                  >
                  >
                  > MISAO 50-100 but not in GCVS
                  >
                  > Very questionable
                  > 52
                  > 56
                  > 59
                  > 64
                  >
                • martin_piers_nicholson
                  Take Misao 98 as an example. BAD NEWS Only 2 data points, March and June 1999. However to my eye quite a few other stars in the field look different as well.
                  Message 8 of 13 , Sep 2, 2006
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                    Take Misao 98 as an example.

                    BAD NEWS
                    Only 2 data points, March and June 1999.

                    However to my eye quite a few other stars in the field look
                    different as well.

                    GCVS didn't include it although it appears in the same issue of IBVS
                    as many MISAO stars that were accepted.


                    GOOD NEWS
                    They differ by a quoted 1.1 magnitudes and the photos clearly show
                    the indicated star has changed in brightness.



                    What I would like is clear guidance on what constitutes proof of
                    sufficient quality and quantity to qualify for inclusion in VSX. If
                    I were to invest time in going through the material it would have to
                    be on the basis of having this framework in place first. (Refer to
                    forthcoming email on priorities in this context)
                  • kawai.sasami
                    ... You have evidently not read up on or learnt about or taken note of the pixy system and its subsequent revised form the pixy2 system. If you had you would
                    Message 9 of 13 , Sep 3, 2006
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                      --- In vsx-dis@yahoogroups.com, "martin_piers_nicholson"
                      <martin_piers_nicholson@...> wrote:
                      >
                      > Take Misao 98 as an example.
                      >
                      > BAD NEWS
                      > Only 2 data points, March and June 1999.
                      >
                      > However to my eye quite a few other stars in the field look
                      > different as well.

                      You have evidently not read up on or learnt about or taken note of the
                      pixy system and its subsequent revised form the pixy2 system.

                      If you had you would know that differences between brightnesses
                      between discordant images are allowed for, correction can be applied
                      given the reasonable assumption that the vast majority of the field
                      stars are constant. Once this form of calibration has been applied
                      any remaining difference in magnitude found for any particular star
                      has a likelihood of being variability, the large the amplitude, the
                      higher the likelihood.

                      As most images were unfiltered highish amplitude red LPVs were
                      predominantly detected in the MISAO system.

                      Incidentally, I am not part of and never was part of MISAO and I shall
                      note that separately.

                      > GCVS didn't include it although it appears in the same issue of IBVS
                      > as many MISAO stars that were accepted.
                      >
                      >
                      > GOOD NEWS
                      > They differ by a quoted 1.1 magnitudes and the photos clearly show
                      > the indicated star has changed in brightness.

                      they were measured, reduced, to show this. Not guessed by eyeball.
                      Granted the photometric calibration is against USNO A2.0 red mags, so
                      the magnitudes are purely MISAOing, but that's the way it was.

                      The original intent was to find incidental asteroids in spare images.
                      PIXY and any presumable precursor thus had to match any and all
                      images to the USNO A2.0 catalogue to find new objects that shouldn't
                      be in the field. Some level of magnitude estimate is also useful for
                      such endeavours, and A2.0 at the time, and still now to some extent,
                      is the only readily available bulk system allowing stars to fainter
                      mags than most amateur imaging. ie Seiichi has a copy. Although I
                      vaguely remember PIXY2 could fetch other data off of the net later on.

                      All form memory, all stuff I learnt by bothering to read the MISAO
                      website in the past.

                      John
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