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ASAS 183136-1815.4

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  • Patrick Wils
    ASAS 183136-1815.4 was found to be a Mira type variable with a period of 209 days (range 12.3-
    Message 1 of 5 , Mar 25, 2007
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      ASAS 183136-1815.4 was found to be a Mira type variable with a period of
      209 days (range 12.3-<14.3V) by ASAS3.
      Brian Skiff's MKTypes.dat file of spectral types contains an entry for
      SS73 167 = UCAC2 24932494 (mag 14.5V), 4.7" from the position of the ASAS
      star (and the precision of the ASAS coordinates is only 6"). SS73 167 is
      a Be star (the source is
      <http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1973ApJ...185..899S>).
      If this is not a chance alignment, and both stars are thus physically
      related, and the Be classification is correct, this might be a symbiotic
      binary. Is anyone interested in investigating this further?

      Patrick




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    • arne
      ... I m observing in Flagstaff late May; if no one has looked at this by then, I ll check it out. Arne
      Message 2 of 5 , Mar 26, 2007
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        Patrick Wils wrote:
        > ASAS 183136-1815.4 was found to be a Mira type variable with a period of
        > 209 days (range 12.3-<14.3V) by ASAS3.
        > Brian Skiff's MKTypes.dat file of spectral types contains an entry for
        > SS73 167 = UCAC2 24932494 (mag 14.5V), 4.7" from the position of the ASAS
        > star (and the precision of the ASAS coordinates is only 6"). SS73 167 is
        > a Be star (the source is
        > <http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1973ApJ...185..899S>).
        > If this is not a chance alignment, and both stars are thus physically
        > related, and the Be classification is correct, this might be a symbiotic
        > binary. Is anyone interested in investigating this further?
        >
        I'm observing in Flagstaff late May; if no one has looked at this by
        then, I'll check it out.
        Arne
      • arne
        ... From MKTypes.dat, the coordinates for SS73 167 = UCAC2 24932494 are: 1973ApJ...185..899S SS73 167 18 31 36.30 -18 15 25.9 U 14.5 V Be I
        Message 3 of 5 , Jun 11, 2007
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          Patrick Wils wrote:
          > ASAS 183136-1815.4 was found to be a Mira type variable with a period of
          > 209 days (range 12.3-<14.3V) by ASAS3.
          > Brian Skiff's MKTypes.dat file of spectral types contains an entry for
          > SS73 167 = UCAC2 24932494 (mag 14.5V), 4.7" from the position of the ASAS
          > star (and the precision of the ASAS coordinates is only 6"). SS73 167 is
          > a Be star (the source is
          > <http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1973ApJ...185..899S>).
          > If this is not a chance alignment, and both stars are thus physically
          > related, and the Be classification is correct, this might be a symbiotic
          > binary. Is anyone interested in investigating this further?
          >
          From MKTypes.dat, the coordinates for SS73 167 = UCAC2 24932494 are:
          1973ApJ...185..899S SS73 167 18 31 36.30 -18 15 25.9 U 14.5 V Be

          I took UBVRI images of this field during my last NOFS observing
          run a couple of weeks ago. This source is present at
          RA (J2000) DEC V B-V V-Rc Rc-Ic V-Ic
          18:31:36.29 -18:15:26.0 15.097 2.636 2.020 2.090 4.125
          and absent on my U-band image (pretty reddened region in Sgr).
          I see no indication that this is a Be star; looks like a typical
          red star to me.

          I've placed 2x2 arcmin images centered on this object at:
          http://www.aavso.org/tmp2/asasi.jpg
          http://www.aavso.org/tmp2/asasr.jpg
          http://www.aavso.org/tmp2/asasv.jpg
          http://www.aavso.org/tmp2/asasb.jpg
          http://www.aavso.org/tmp2/asasu.jpg
          (sorry about the seeing, but it is never great with the 1.0m)

          Sanduleak and Stephenson's coordinates and information are:
          star RA (B1950) DEC p v n type
          167 18:28:40.7 -18:17:40 14.0 12.0 5 Be! new
          where Be! indicates extreme Be-like object, and n is the last
          resolvable hydrogen line in the emission spectrum. Coordinates were
          derived from measures made on the objective prism plates and should
          be reliable to within several seconds of arc.

          Straight precession of the SS coordinates is
          18:31:36.3 -18:15:29

          All in all, it looks like either the SS catalog picked the wrong
          object, or they caught a symbiotic system in outburst; that
          would agree with their estimate of mv=12. Nothing in the field
          is particularly blue.
          Arne
        • Patrick Wils
          ... The mv=12 may correspond to the maximum magnitude of the Mira star as well (see
          Message 4 of 5 , Jun 12, 2007
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            > All in all, it looks like either the SS catalog picked the wrong
            > object, or they caught a symbiotic system in outburst; that
            > would agree with their estimate of mv=12.

            The mv=12 may correspond to the maximum magnitude of the Mira star as well
            (see
            <http://www.astrouw.edu.pl/cgi-gp/asas_plot_raw_all?183136-1815.4,asas3,0,500,0>
            and <http://skydot.lanl.gov/nsvs/star.php?num=16676109&mask=15636>). You
            likely observed the Mira star near minimum, Arne.
            A lot of the Be stars from SS73 have been recovered during other surveys,
            but not this one. There is always a chance of a typo in the catalog
            coordinates of course (and it seems that way here), but what are the odds
            it then corresponds to within 5" of a Mira variable?

            Patrick


            --- arne <arne@...> wrote:

            > Patrick Wils wrote:
            > > ASAS 183136-1815.4 was found to be a Mira type variable with a period
            > of
            > > 209 days (range 12.3-<14.3V) by ASAS3.
            > > Brian Skiff's MKTypes.dat file of spectral types contains an entry for
            > > SS73 167 = UCAC2 24932494 (mag 14.5V), 4.7" from the position of the
            > ASAS
            > > star (and the precision of the ASAS coordinates is only 6"). SS73
            > 167 is
            > > a Be star (the source is
            > >
            > <http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1973ApJ...185..899S>).
            >
            > > If this is not a chance alignment, and both stars are thus physically
            > > related, and the Be classification is correct, this might be a
            > symbiotic
            > > binary. Is anyone interested in investigating this further?
            > >
            > From MKTypes.dat, the coordinates for SS73 167 = UCAC2 24932494 are:
            > 1973ApJ...185..899S SS73 167 18 31 36.30 -18 15 25.9 U
            > 14.5 V Be
            >
            > I took UBVRI images of this field during my last NOFS observing
            > run a couple of weeks ago. This source is present at
            > RA (J2000) DEC V B-V V-Rc Rc-Ic V-Ic
            > 18:31:36.29 -18:15:26.0 15.097 2.636 2.020 2.090 4.125
            > and absent on my U-band image (pretty reddened region in Sgr).
            > I see no indication that this is a Be star; looks like a typical
            > red star to me.
            >
            > I've placed 2x2 arcmin images centered on this object at:
            > http://www.aavso.org/tmp2/asasi.jpg
            > http://www.aavso.org/tmp2/asasr.jpg
            > http://www.aavso.org/tmp2/asasv.jpg
            > http://www.aavso.org/tmp2/asasb.jpg
            > http://www.aavso.org/tmp2/asasu.jpg
            > (sorry about the seeing, but it is never great with the 1.0m)
            >
            > Sanduleak and Stephenson's coordinates and information are:
            > star RA (B1950) DEC p v n type
            > 167 18:28:40.7 -18:17:40 14.0 12.0 5 Be! new
            > where Be! indicates extreme Be-like object, and n is the last
            > resolvable hydrogen line in the emission spectrum. Coordinates were
            > derived from measures made on the objective prism plates and should
            > be reliable to within several seconds of arc.
            >
            > Straight precession of the SS coordinates is
            > 18:31:36.3 -18:15:29
            >
            > All in all, it looks like either the SS catalog picked the wrong
            > object, or they caught a symbiotic system in outburst; that
            > would agree with their estimate of mv=12. Nothing in the field
            > is particularly blue.
            > Arne
            >




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          • arne
            ... You may be correct about the Mira maximum; however, I based my comment on the fact that it was brighter than when I observed it, and showed strong emission
            Message 5 of 5 , Jun 12, 2007
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              Patrick Wils wrote:
              >>All in all, it looks like either the SS catalog picked the wrong
              >>object, or they caught a symbiotic system in outburst; that
              >>would agree with their estimate of mv=12.
              >
              >
              > The mv=12 may correspond to the maximum magnitude of the Mira star as well
              > (see
              > <http://www.astrouw.edu.pl/cgi-gp/asas_plot_raw_all?183136-1815.4,asas3,0,500,0>
              > and <http://skydot.lanl.gov/nsvs/star.php?num=16676109&mask=15636>). You
              > likely observed the Mira star near minimum, Arne.
              > A lot of the Be stars from SS73 have been recovered during other surveys,
              > but not this one. There is always a chance of a typo in the catalog
              > coordinates of course (and it seems that way here), but what are the odds
              > it then corresponds to within 5" of a Mira variable?
              >
              You may be correct about the Mira maximum; however, I based my
              comment on the fact that it was brighter than when I observed it,
              and showed strong emission lines. There is no evidence of strong
              emission in my photometry; for example, Rc seems to be perfectly
              normal.

              I'll ask Ulisse to get a spectrum as a final check.
              Arne
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