Wiyn Open Cluster Study. Xxxvi. Spectroscopic Binary Orbits in NGC 188

Abstract

We present 98 spectroscopic binary orbits resulting from our ongoing radial-velocity survey of the old (7 Gyr) open cluster NGC 188. All but 13 are high-probability cluster members based on both radial-velocity and proper-motion membership analyses. 15 of these member binaries are double lined. Our stellar sample spans a magnitude range of 10.8≤V≤16.5 (1.14-0.92 M ⊙ ) and extends spatially to 17 pc (∼13 core radii). All of our binary orbits have periods ranging from a few days to on the order of 10 3 days, and thus are hard binaries that dynamically power the cluster. For each binary, we present the orbital solutions and place constraints on the component masses. Additionally, we discuss a few binaries of note from our sample, identifying a likely blue straggler -blue straggler binary system (7782), a double-lined binary with a secondary star which is under-luminous for its mass (5080), two potential eclipsing binaries (4705 and 5762), and two binaries which are likely members of a quadruple system (5015a and 5015b).

Wiyn Open Cluster Study. Lxvi. Spectroscopic Binary Orbits in the Young Open Cluster M35 (Ngc 2168)

“…Using the same procedure outlined in Geller et al (2009), we can fit an orbital solution to RV measurements of velocityvariable stars, provided we have a sufficient number of observations. Here we present orbital solutions for 80 binaries.…”

Bayesian Investigation of Isochrone Consistency Using the Old Open Cluster NGC 188

“…Along with photometry, we take advantage of the multiepoch radial-velocity data from Geller et al (2008Geller et al ( , 2009; and additional observations from the continuation of their radialvelocity survey). This radial-velocity sample contains at least three observations for nearly every solar-type star from ∼1.5 mag below the cluster turn-off up to the tip of the giant branch (∼0.95-1.15 M  ) within a 1°diameter region centered on NGC 188 (corresponding to a radius of ∼17 pc or roughly 13 core radii), and spans a monitoring baseline of more than a decade for many stars.…”

Characterizing a cluster’s dynamic state using a single epoch of radial velocities

“…Because multiple epochs of data are available for nearly all of the 1108 stars we are able to run the procedure on three singleepoch radial velocity data sets with only minimal duplication between the data sets. The radial velocities and measurement errors were taken from Geller et al (2009). The first three panels in Fig.…”