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 $F_{\rm H\delta}/F_{\rm H\gamma}$ 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 $\mu$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

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

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 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