510,680 research outputs found
Mira Variable Stars From LAMOST DR4 Data: Emission Features, Temperature Types, and Candidate Selection
Based on an extensive spectral study of a photometrically confirmed sample of
Mira variables, we find a relationship between relative Balmer emission-line
strength and spectral temperature of O-rich Mira stars. The flux ratio increases from less than unity to five as
stars cool down from M0 to M10, which is likely driven by increasing TiO
absorption above the deepest shock-emitting regions. We also discuss the
relationship between the equivalent widths of the Balmer emission lines and the
photometric luminosity phase of our Mira sample stars. Using our 291 Mira
spectra as templates for reference, 191 Mira candidates are newly identified
from the LAMOST DR4 catalog. We summarize the criteria adopted to select Mira
candidates based on emission-line indices and molecular absorption bands. This
enlarged spectral sample of Mira variables has the potential to contribute
significantly to our knowledge of the optical properties of Mira stars and will
facilitate further studies of these late-type, long-period variables.Comment: 21 pages; ApJS, in pres
Born Again Protoplanetary Disk Around Mira B
The Mira AB system is a nearby (~107 pc) example of a wind accreting binary
star system. In this class of system, the wind from a mass-losing red giant
star (Mira A) is accreted onto a companion (Mira B), as indicated by an
accretion shock signature in spectra at ultraviolet and X-ray wavelengths.
Using novel imaging techniques, we report the detection of emission at
mid-infrared wavelengths between 9.7 and 18.3 m from the vicinity of Mira
B but with a peak at a radial position about 10 AU closer to the primary Mira
A. We interpret the mid-infrared emission as the edge of an optically-thick
accretion disk heated by Mira A. The discovery of this new class of accretion
disk fed by M-giant mass loss implies a potential population of young planetary
systems in white-dwarf binaries which has been little explored, despite being
relatively common in the solar neighborhood.Comment: Accepted for Ap
A model of Mira's cometary head/tail entering the Local Bubble
We model the cometary structure around Mira as the interaction of an AGB wind
from Mira A, and a streaming environment. Our simulations introduce the
following new element: we assume that after 200 kyr of evolution in a dense
environment Mira entered the Local Bubble (low density coronal gas). As Mira
enters the bubble, the head of the comet expands quite rapidly, while the tail
remains well collimated for a 100 kyr timescale. The result is a
broad-head/narrow-tail structure that resembles the observed morphology of
Mira's comet. The simulations were carried out with our new adaptive grid code
WALICXE, which is described in detail.Comment: 12 pages, 8 figures (4 in color). Accepted for publication in The
Astrophysical Journa
Improvement on work measurement at Pau Mira Frozen Food Industry
The record of highest sales for one day is 20000 buns and the manpower for Pau Mira factory is only 18 persons. Special feature for Pau Mira is about the full of stuffing and many choices of flavor. Hot selling bun flavor is red bean bun and chocolate bun. For example, Bun Mira contains many flavors such as red bean bun, coconut, yam, chocolate, chicken, durian and it is enables to be food supplies to West Malaysia, not only limited to area Pagoh. The workflow for Pau Mira factory includes ingredient selection, dough kneading, and bun formation, fermentation, steaming, cooling and packaging. Table 5.1 shows the process of making pau started from dough kneading until the packaging process
THE SECRET TRIBUNAL OR, THE COURT OF WINCESLAUS A MYSTERIOUS TALE [Transcript]
Set in Bavaria, The Secret Tribunal, follows the young maiden Mira, who is being raised by her two parents, Old Lindhom and Ms. Lindholm and is pursued by the young Lipstolf. Lipstolf, a member of the Court of Wenceslaus, is told to leave as he and Mira can never be together due to a family secret. He leaves and becomes a knight. Mira gains entry to the Court of Wenceslaus as an attendant to Wenceslaus’ wife Sophia. Mira ingratiates herself to Sophia, much to the chagrin of the Countess Ormsberg who wishes for her daughter to be a favorite in the court.
Mira plays her harp for Sophia in order to help Sophia deliver a male heir to Wenceslaus, who then gives birth to a stillborn baby girl. Seizing the opportunity, Duchess Ormsberg charges Mira with sorcery. Mira is summoned to a secret tribunal. During the proceedings Lipstolf appears and helps to exonerate her as well as revealing Mira’s true aristocratic lineage. Mira now goes off to reside with her father, a Count. However, she is pursued by the secret tribunal and goes into hiding in a convent. News reaches her that Lipstolf has now been accused of murder and will face the same tribunal. Lipstolf is acquitted by the tribunal and finds Mira in the convent. Mira is reunited with Listolf and Lindholm and all live well knowing the secret tribunal is now under the authority of a friend and will no longer pursue them.https://epublications.marquette.edu/english_gothic/1017/thumbnail.jp
The radio continuum spectrum of Mira A and Mira B up to submillimeter wavelengths
We present new measurements of the flux densities at submillimeter
wavelengths based on ALMA band 7 (338 GHz) and band 9 (679 GHz) observations to
better constrain the origin of the continuum emission of the Mira AB binary
system and to check its orbit. We have measured the Mira A and Mira B continuum
in ALMA band 7, with a resolution of ~0"31, and for the first time in ALMA band
9, with a resolution of ~0"18. We resolved the binary system at both bands, and
derived the continuum spectral index of the stars and their relative position.
We also analyzed ALMA SciVer data obtained in bands 6 and 3. Measurements at
centimeter wavelengths obtained by other authors have been included in our
study of the spectral energy distribution of the Mira components. The Mira A
continuum emission has a spectral index of 1.98+-0.04 extending from
submillimeter down to centimeter wavelengths. The spectral index of the Mira B
continuum emission is 1.93+-0.06 at wavelengths ranging from submillimeter to
~3.1 mm, and a shallower spectral index of 1.22+-0.09 at longer wavelengths.
The Mira A continuum emission up to submillimeter wavelengths is consistent
with that of a radio photosphere surrounding the evolved star for which models
predict a spectral index close to 2. The Mira B continuum emission cannot be
described with a single ionized component. An extremely compact and dense
region around the star can produce the nearly thermal continuum measured in the
0.4-3.1 mm wavelength range, and an inhomogeneous, less dense, and slightly
larger ionized envelope could be responsible for the emission at longer
wavelengths. Our results illustrate the potential of ALMA for high precision
astrometry of binary systems. We have found a significant discrepancy of ~14
milliarcsec between the ALMA measurements and the predicted orbit positions.Comment: 6 pages, 3 figures, 2 tables, accepted for publication in Astronomy
and Astrophysic
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