Observations of the sx phoenicis star xx cygni
This presentation is the property of its rightful owner.
Sponsored Links
1 / 22

Observations of the SX Phoenicis Star XX Cygni PowerPoint PPT Presentation


  • 92 Views
  • Uploaded on
  • Presentation posted in: General

Observations of the SX Phoenicis Star XX Cygni. X.H. Yang Beijing Normal University 2010.4.1. Contents. Introduction of the SX Phe stars New observations Data reduction Light curves Analysis Conclusions. Introduction. δ Scuti Stars: 1.The SX Phoneicis stars

Download Presentation

Observations of the SX Phoenicis Star XX Cygni

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Observations of the SX Phoenicis Star XX Cygni

X.H. Yang

Beijing Normal University

2010.4.1


Contents

  • Introduction of the SX Phe stars

  • New observations

  • Data reduction

  • Light curves

  • Analysis

  • Conclusions


Introduction

δ Scuti Stars:

1.The SX Phoneicis stars

2.High-amplitude δ Scuti Stars (HADS)

Period changes:

Period increasing and period decreasing were detected in different

δ Scuti Stars

  • The SX Phoenicis stars:

    • Found in the field stars

    • Found in the blue straggler populations of globular clusters

  • short-period

  • Single- or multiple-mode pulsations


Importance of studying SX Phe stars

1.Studying stellar evolution

2. Potential targets for Asterseismology


  • XX Cygni:

    20h03m15.6 58°57'17.0"

    Spectral type: A5-F5,

    V=11.m7, P≈0.d1349, △V=0.m84

    Mass:1 Msun [Fe/H]=-0.49 dex

    Teff: 7530 K Radial Velocity=-108 km/s


  • Discovered by Ceraski (1904)

  • Constant period, marked by occasional discontinuous period changes (Szeidl & Mahdy 1981)

  • Single-mode pulsation (Hintz & Joner1997)

  • Both amplitude and period changes (Zhou et al. 2001)

  • If the small secondary peak(maximum) is real,it is transient (Blake 2002)


The secondary peak or maximum

From BLAKE

Period Changes in SX Phoenicis Stars. II. XX Cygni


New observations

  • Telescope used in observations

    1. The 85-cm telescope located at the Xinglong Station of NAOC

    Focal ratio: 3.27 ;Focal length: 2780mm

    CCD camera: CCD,PI1024 BFT

    Filters: Standard Johnson-Cousin-Bessel UBVRI

    Field of view: 16’.5×16’.5

    2.The 60-cm telescope located in Kunming (Yunnan Astronomical Observatory)


Journal of new observations in V band for XX Cyg


  • Totally, 24 nights of data in V band


Data Reduction

Data reduction was performed using the APPHOT program in IRAF:

1.Bias and Dark correction, Flat fielding

2.Multiple aperture photometry

3.Determination of the best aperture


Example of the best aperture selected:

FWHM:

4 pixel


Field of view:

16’.5*16’.5

Xinglong


Light Curves

2007

07.15-08.30

Xinglong 85cm

Error:

0.004-0.02


2008.08.31

Xinglong

Error:

0.003


2009

07.09

-10.17

Xinglong

Error:

0.003-0.02

Kunming

60cm

Kunming


Analysis

Observed new times of maximum: 37


Fourier analysis:

Software: Period04

Data set: 2007.08

8 nights of observations


Frequency solutions of XX Cyg


Fitting curves


Conclusions

No secondary peaks were found in our data.

  • Next work:

    • O-C analysis

    • Period change analysis


  • Login