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
Photometric observations of YZ Boo in the uvby beta system obtained in summer, 1982, with the two-channel sky-compensating photometer on the 61-cm reflecting telescope at West Mountain Observatory are reported. The period is calculated from both the present and published light maxima as 0.104091593 days. The phase variation of the different photometric parameters is given in tables and graphs. A reddening value E(b-y) = 0.018 m is found, and further parameters are estimated, using the model atmospheric grid of Breger (1977) in some cases: T(eff) = 7590 K, log g = 3.95, Fe/H = -0.025, M(bol) = 1.7, mean radial velocity = -20 km/sec, and total velocity range = 35 km/sec. An attempted Wesselink radius calculation was unsuccessful. YZ Boo is classified as a normal dwarf cepheid of Population I.
Intermediate-band (uvbyβ) photometry has been secured of galactic foreground A and F stars in the direction of the SMC and LMC. The photometry yields mean color-excess values of 〈E(b-y)⌨ = 0ṃ013 for the SMC and 〈E(b-y)⌨ = 0ṃ024 for the LMC. By adopting de Vaucouleurs' apparent distance moduli of the Clouds and absorptions of AB = 0ṃ08 (SMC) and AB = 0ṃ15 (LMC) we find true distance moduli of ¼₀ = 18.85 (SMC) and ¼₀ = 18.59 (LMC).
New photometric data in the uvbyβ and (khg₂) systems are presented for 41 cepheids. Intrinsic relations are established, using the color indices determined from field stars of five cepheids, which allow color excesses to be obtained for the other 36 variables by means of curve-matching techniques. It appears that serious systematic errors are present in previously published color excesses.
Photometric (uvbyβ) observations of XX Cyg (RRs variable) are described. XX Cyg has a large light amplitude (0ṃ77 in V), is reddened by 0ṃ025, and has a small m₁ value (m₁ = 0ṃ11) indicating XX Cyg is metal poor. The mean effective surface gravity and temperature are = 3.34 and = 7250 K. The surface gravity is smaller than the surface gravities of other dwarf cepheids of similar period. Single-trail spectrograms of XX Cyg indicate the star is metal poor with a total velocity range of 34 km s⁻¹ and a mean radial velocity of — 110 km s⁻¹.
Radial velocity measurements secured from a single-trail spectrogram of DY Her yield a mean velocity of -49 km s⁻¹. The velocity curve has been integrated to obtain a radius-excursion curve. A radius of R = 2.7 R⊙ is found from Wesselink's method by utilizing our radius-excursion curve and the photometry of Breger, Campos, and Roby (1978).