Graduate Student Savanah Turner Publishes Study of over 300 L and T dwarfs

BYU Astronomy Research Group Joins the Astrophysical Research Consortium (ARC)

As of January 2021 BYU will be a member of the ARC Consortium (Link to Consortium) with access to the ARC 3.5-m telescope and the 0.5-m ARCSAT telescope.  The primary use of the ARC 3.5-m telescope time is for graduate student projects.  This provides a wide array of instrumentation that is currently being used to study objects in the solar system all the way to studies of the large scale structure of the Universe.

Other BYU Astronomy Facilities

In addition to our telescope time from the ARC consortium, we operate a number of our own astronomical facilities

West Mountain Observatory (West Mountain)

This is our mountain observatory at about 6600 ft above sea level.  This consists of three telescopes: 0.9-m, 0.5-m, and a 0.32-m. It is a 40 minute drive that ends in a 5 miles drive up a dirt road. The mountain itself can be seen from campus. We don't provide any tours of this facility.

Orson Pratt Observatory

The Orson Pratt Observatory is named for an early apostle of the Church of Jesus Christ of Latter-Day Saints.  It is our campus telescope facility and contains a wide variety of telescopes for student research and public outreach. We operate a 24" PlaneWave telescope in the main campus dome, plus a 16", two 12", one 8", and a 6" telescope on our observation deck.  The telescopes are all fully robotic. Beyond this we have a large sections of telescopes used on public nights.

Royden G. Derrick Planetarium (Planetarium)

This is a 119 seat, 39" dome planetarium with acoustically treated walls to allow it's use as a lecture room. Recently we upgraded to an E&S Digistar7 operating system with 4K projectors.  The planetarium is used for teaching classes, public outreach, and astronomy education research projects.





Selected Publications

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A Note on the Paper by C. E. Palmer, "The Stratospheric Vortex in Winter"
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A photometric and spectrographic study of sx phoenicis
Simultaneous photometric (uvbybeta) and spectrographic observations of SX Phe are described. Analysis of the light and velocity frequency spectra are performed. It is shown that all frequencies detected are harmonics or combinations of the fundamental and first harmonic frequencies. Intrinsic (b-y) and c1 values used in conjunction with a model-atmosphere grid appropriate for a star with [M/H] = - 1.0 yields [T(eff)] = 7630 K and [log g] = 3.90. Standard evolutionary models indicate the mass is 1.13 M. and [M(v)] value is + 2.9. The radial-velocity data indicate a mean radial velocity of - 37 km/s and a total range of 38 km/s.
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VRI photometric properties of M-type giants
D. Thomas and C. G. Christensen (et al.)

In this paper the results of a study of the relation between M-giant spectral types and their intrinsic color indices are presented. The result of a discussion of the absolute magnitudes of M-type giants, determined by different authors, is also given. These results will be used for the determination of the space density of M giants in the galactic plane.

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Absolute spectral energy-distributions and [fe-h] values of metal-poor stars and globular clusters
Absolute spectral energy distributions for 65 metal-poor stars, spanning a wide range in temperature, luminosity, and metal content, are given. Five local globular clusters and five M31 globulars are also described. The wavelength index sequence of O'Connell (1970, 1973) has been used. Continuum and feature indices are compared internally and with those of the Population I stellar sequence of O'Connell. His discussion of the usefulness of these indices as temperature, luminosity, and metallicity criteria is extended to metal-poor objects. Empirical relationships between /Fe/H/ color, and certain feature indices have been calibrated and applied to 19 objects with previously undetermined /Fe/H/ values.
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Note on the Spectrum of SX Phoenicis

Single-trail spectra of SX Phe have been obtained covering many cycles of this short-period dwarfcepheid variable at a dispersion of 18 Å mm⁻¹. The rapid changes in line intensities and the line doubling reported by Stock and Tapia (1971a) from 40 Å mm⁻¹ plates are not evident in our spectra.

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Luminosity function of nearby galaxies
The luminosity function of nearby field galaxies has been determined from a sample of 231 "normal" galaxies with m 8 :.::;; 11.85. The sample has been confined to galactic latitudes above ± 20 • and excludes the Virgo cluster region. Absolute magnitudes for galaxies with radial velocities exceeding 400 km sec-1 have been based on the Hubble law with H = 50 km sec-1 Mpc-1• Other distance criteria have been used for systems of lower velocity. For galaxies brighter than M 8 = 21.05 the observed differential luminosity function is well represented by logcj>(M 8 ) = (27.65±0.31) + (1.462±0.014)M 8 . Fainter systems are described by logcj>(M 8 ) = (4.37 ±0.44) + (0.355 ±0.004)M 8 • Resolution of the luminosity functfon into eight morphological types reveals moderately strong dependence on type. The results of varying the Hubble parameter and the absorption law are demonstrated to be small except for a displacement of the entire function in the log cj>, M 8 plane. Including the Virgo cluster region is shown to unrealistically distort the bright end of the function. Northern and southern luminosity functions agree in shape but not in position in the log cj>, M 8 plane. Not all of the difference can be attributed to the higher galaxian density of the northern hemisphere. It may be that the asymmetry is only apparent, arising out of the peculiar motion of the Local Group.