AL 3 (BH 261), previously classified as a faint open cluster candidate, is shown to be a new globular cluster in the Milky Way, by means of B, V and I Color-Magnitude Diagrams. The main feature of AL 3 is a prominent blue extended Horizontal Branch. Its Color-Magnitude Diagrams match those of the intermediate metallicity cluster M 5. The cluster is projected in a rich bulge field, also contamin...

I-hsing (Yixing in pinyin) was a buddhist monk, an astronomer and a mathematician during the T’ang dynasty in China. He formulated an astronomical system, called Ta-yen li (Grand Expansion Calendrical System, Dayan li in pinyin), completed in 727 A.D. A few years before, in 718 A.D., Ch’üt’an Hsi-ta (Gautama Siddhārtha), an Indian astronomer who was appointed an ”astronomer royal” in the T’ang ...

Ptolemy’s Theorem in Euclidean geometry, named after the Greek astronomer and mathematician Ptolemy, is well-known. By means of relativistic model hyperbolic we translate from geometry into Lobachevsky Bolyai. The based on Einstein addition relativistically admissible velocities and, as such, it coincides with well-known Beltrami–Klein ball geometry. translation achieved by trigonometry, called...

We present infrared (IR) and optical echelle spectra of the Classical T Tauri star TW Hydrae. Using the optical data, we perform detailed spectrum synthesis to fit atomic and molecular absorption lines and determine key stellar parameters: Teff = 4126± 24 K, log g = 4.84± 0.16, [M/H]= −0.10± 0.12, v sin i = 5.8± 0.6 km s. The IR spectrum is used to look for Zeeman broadening of photospheric abs...

Using the known detection limits for high-resolution imaging observations and the statistical properties of true binary and line-of-sight companions, we estimate the binary fraction of Kepler exoplanet host stars. Our speckle imaging programs at the WIYN 3.5m and Gemini North 8.1-m telescopes have observed over 600 Kepler objects of interest (KOIs) and detected 49 stellar companions within ∼1 a...

We present spectral classification of 105 northern stars with proper motions larger than 0.5 yr, which were recently discovered by us in a survey of high proper motion stars at low galactic latitudes. The final tally is as follows: 54 M dwarfs, 25 sdK and sdM subdwarfs, 14 esdK and esdM extreme subdwarfs, and 12 DA and DC white dwarfs. Among the most interesting cases, we find one star to be th...

IN 1960, ASTRONOMER FRANK DRAKE turned the radio telescope at National Radio Astronomy Observatory in Green Bank, W.Va., toward two nearby sunlike stars to search for transmissions from intelligent extraterrestrial societies. With a pair of headphones, Drake listened Tau Ceti and Epsilon Eridani total 150 hours across multiple sessions. He heard nothing, except single false positive that out be...