Confirmation of Errors in Hipparcos Parallaxes from HST/FGS Astrometry of the Pleiades

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

9 pages, 10 tables, 6 figures; AJ in press (March 2005 issue)

Scientific paper

10.1086/427860

We present absolute trigonometric parallaxes and relative proper motions for three members of the Pleiades star cluster, obtained with HST's Fine Guidance Sensor 1r, a white-light interferometer. We estimate spectral types and luminosity classes of the stars comprising the astrometric reference frame from R \approx 2,000 spectra, VJHK photometry, and reduced proper motions. From these we derive estimates of absolute parallaxes and introduce them into our model as observations with error. We constrain the three cluster members to have a 1 sigma dispersion in distance less than 6.4 pc, and find an average pi_{abs}=7.43+-0.17+-0.20 milliseconds of arc, where the second error is systematic due to member placement within the cluster. This parallax corresponds to a distance of 134.6+-3.1 pc or a distance modulus of (m-M)=5.65+-0.05 for these three Pleiads, presuming a central location. This result agrees with three other independent determinations of the Pleiades distance. Presuming that the cluster depth systematic error can be significantly reduced because of the random placement of these many members within the cluster, these four independent measures yield a best-estimate Pleiades distance of pi_{abs}=7.49+-0.07 milliseconds of arc, corresponding to a distance of 133.5+-1.2 pc or a distance modulus of (m-M)=5.63+-0.02. This resolves the dispute between the main sequence fitting and the Hipparcos distance moduli in favor of main sequence fitting.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Confirmation of Errors in Hipparcos Parallaxes from HST/FGS Astrometry of the Pleiades does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Confirmation of Errors in Hipparcos Parallaxes from HST/FGS Astrometry of the Pleiades, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Confirmation of Errors in Hipparcos Parallaxes from HST/FGS Astrometry of the Pleiades will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-402676

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.