Distant Stars

Polarization of Light From Distant Stars by Interstellar Medium.

The Radial Velocities of the More Distant Stars.

As a result of the work of Kapteyn, Campbell, and Boss it has been recognized for some years that the linear motions of the brighter stars vary with their spectral types, the velocities of the solar type stars being higher than those of types B and A. It is equally well-known, however, that the solar type stars in general have larger proper motions and so are much nearer to the sun than those o...

New Distant Companions to Known Nearby Stars. Ii. Faint Companions of Hipparcos Stars and the Frequency of Wide Binary Systems

We perform a search for faint, common proper motion companions of Hipparcos stars using the recently published LSPM-north catalog of stars with proper motion μ > 0.15 yr−1. Our survey uncovers a total of 521 systems with angular separations 3 < ∆θ < 1500, with 15 triples and 1 quadruple. Our new list of wide systems with Hipparcos primaries includes 130 systems identified here for the first tim...

Unweighted p-center problem on extended stars

An extended star is a tree which has only one vertex with degree larger than two. The -center problem in a graph  asks to find a subset  of the vertices of  of cardinality  such that the maximum weighted distances from  to all vertices is minimized. In this paper we consider the -center problem on the unweighted extended stars, and present some properties to find solution.

Induced subgraphs of graphs with large chromatic number. XII. Distant stars

The Gyárfás-Sumner conjecture asserts that if H is a tree then every graph with bounded clique number and very large chromatic number contains H as an induced subgraph. This is still open, although it has been proved for a few simple families of trees, including trees of radius 2, some special trees of radius 3, and subdivided stars. These trees all have the property that their vertices of degr...