Mira Variable Stars from LAMOST DR4 Data: Emission Features, Temperature Types, and Candidate Selection

AbstractWe use astrometry to measure the distances to Galactic Mira variable stars. Our purpose is to determine a precise period–luminosity relation (PLR). At present, we do not have a precise PLR for Galactic Mira stars because of the large uncertainties affecting their distance estimates. To reduce the uncertainties, we adopted the Very Long Baseline Interferometry method and measured annual parallaxes of Mira variable stars with VERA. In addition to our previous results, we obtained three new distances for Mira variable stars. Based on our observations, the typical uncertainty in a given distance measurement is reduced to below 10%. At this conference, we present the current status of our project. To establish a precise Galactic PLR, we continue to observe more Mira variables. In addition, the apparent magnitudes of the target stars should be studied carefully.

Download Full-text

Long-term polarization observations of Mira variable stars suggest asymmetric structures

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313015068 ◽

2013 ◽

Vol 9 (S301) ◽

pp. 463-464 ◽

Cited By ~ 1

Author(s):

Hilding R. Neilson ◽

Richard Ignace ◽

Gary D. Henson

Keyword(s):

Position Angle ◽

Variable Stars ◽

The Other ◽

Asymmetric Structure ◽

Polarization Measurements ◽

Asymmetric Structures ◽

Mira Variable ◽

Regular Variable ◽

Polarization Fraction

AbstractMira and semi-regular variable stars have been studied for centuries but continue to be enigmatic. One unsolved mystery is the presence of polarization from these stars. In particular, we present 40 years of polarization measurements for the prototype o Ceti and V CVn and find very different phenomena for each star. The polarization fraction and position angle for Mira is found to be small and highly variable. On the other hand, the polarization fraction for V CVn is large and variable, from 2–7%, and its position angle is approximately constant, suggesting a long-term asymmetric structure. We suggest a number of potential scenarios to explain these observations.

Download Full-text

Linear and nonlinear models of Mira variable stars

10.31274/rtd-180813-7973 ◽

1982 ◽

Author(s):

Dale A. Ostlie

Keyword(s):

Nonlinear Models ◽

Variable Stars ◽

Mira Variable ◽

Linear And Nonlinear

Download Full-text

VLBA observations of SiO masers towards Mira variable stars

Astronomy and Astrophysics ◽

10.1051/0004-6361:20031597 ◽

2004 ◽

Vol 414 (1) ◽

pp. 275-288 ◽

Cited By ~ 79

Author(s):

W. D. Cotton ◽

B. Mennesson ◽

P. J. Diamond ◽

G. Perrin ◽

V. Coudé du Foresto ◽

...

Keyword(s):

Variable Stars ◽

Mira Variable

Download Full-text

Wonderful Mira

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2008.0167 ◽

2008 ◽

Vol 366 (1884) ◽

pp. 4429-4440 ◽

Cited By ~ 2

Author(s):

Christopher John Wareing

Keyword(s):

Extended Period ◽

Variable Stars ◽

Bow Shock ◽

Primary Star ◽

Mira Variable ◽

Ram Pressure ◽

Evolutionary Context ◽

Bow Shocks ◽

The Subject ◽

Brightness Variability

Since being named ‘wonderful’ in the seventeenth century for its peculiar brightness variability, Mira A has been the subject of extensive research and become the prototype for a whole class of ‘Mira’ variable stars. The primary star in a binary system, Mira A is reaching the end of its life and currently undergoing an extended period of enhanced mass loss. Recent observations have revealed a surrounding arc-like structure and a stream of material stretching 12 light years away in opposition to the arc. In this article, I review recent modelling of this cometary appearance as a bow shock with an accompanying tail of material ram pressure stripped from the head of the bow shock, place Mira in an evolutionary context, predict its future with reference to the similar star R Hya and planetary nebula Sh 2-188, and speculate some avenues of research both on Mira itself and on other ‘Mira-like’ stars with bow shocks and tails. I also discuss the implications of this discovery for our own star, the Sun.

Download Full-text

Infrared Light Curves of Mira Variable Stars from [ITAL]COBE[/ITAL] DIRBE Data

The Astronomical Journal ◽

10.1086/338647 ◽

2002 ◽

Vol 123 (2) ◽

pp. 948-964 ◽

Cited By ~ 32

Author(s):

Beverly J. Smith ◽

David Leisawitz ◽

Michael W. Castelaz ◽

Donald Luttermoser

Keyword(s):

Variable Stars ◽

Light Curves ◽

Infrared Light ◽

Mira Variable

Download Full-text

Tomography of the Atmosphere of the Mira Variable Z Oph

International Astronomical Union Colloquium ◽

10.1017/s0252921100016729 ◽

2002 ◽

Vol 185 ◽

pp. 428-431

Author(s):

A. Jorissen ◽

M. Dedecker ◽

B. Plez ◽

R. Alvarez ◽

D. Gillet ◽

...

Keyword(s):

Shock Wave ◽

Velocity Field ◽

Optical Spectrum ◽

Variable Stars ◽

Pulsating Stars ◽

Long Period ◽

Synthetic Spectra ◽

Mira Variable ◽

Period Variable ◽

Tomographic Technique

AbstractThe new tomographic technique devised by Alvarez et al. (2000) to explore the velocity field across the atmosphere of long-period variable stars (LPVs) is applied to the Mira variable Z Oph. The method cross-correlates the optical spectrum with numerical masks constructed from synthetic spectra and probing layers of increasing depths. This technique reveals that the line doubling often observed in LPVs around maximum light is the signature of the shock wave propagating in the atmosphere of these pulsating stars.

Download Full-text