83 citations · 437 across the 13 of their papers we have counts for
13 papers
Hypervelocity star candidates from Gaia DR2 and DR3 proper motions and parallaxes
Ralf-Dieter Scholz
Hypervelocity stars (HVSs) unbound to the Galaxy can be formed with extreme stellar interactions. Observational evidence comes from measurements of radial velocities (RVs) of objec…
Gaia-supported re-discovery of a remarkable weak line quasar from a variability and proper motion survey
H. Meusinger, R. -D. Scholz
We demonstrate that VPMS J170850.95+433223.7 is a weak line quasar (WLQ) which is remarkable in several respects. It was already classified as a probable quasar two decades ago, bu…
An ancient F-type subdwarf from the halo crossing the Galactic plane
R. -D. Scholz, U. Heber, C. Heuser +3
AIMS: We selected the bluest object, WISE~J07252351, from Luhman's new high proper motion (HPM) survey based on observations with the Wide-field Infrared Survey Explorer (WISE)…
Two very nearby (d ~ 5 pc) ultracool brown dwarfs detected by their large proper motions from WISE, 2MASS, and SDSS data
R. -D. Scholz, G. Bihain, O. Schnurr +1
Aims: WISE provides an infrared all-sky survey which aims at completing our knowledge on the possibly dramatically increasing number of brown dwarfs with lower temperatures. We sea…
The Hyper-MUCHFUSS project: probing the Galactic halo with sdB stars
A. Tillich, U. Heber, S. Geier +7
High-velocity stars in the Galactic halo, e.g. the so-called hyper-velocity stars (HVS), are important tracers of the properties of the dark matter halo, in particular its mass. Ba…
A halo blue straggler on a highly eccentric retrograde orbit
A. Tillich, N. Przybilla, R. -D. Scholz +1
Blue straggler, which are stars that appear to be younger than they should be, are an important population of unusual stars in both stellar clusters and the halo field of the Galax…
Hip 63510C, Hip 73786B, and nine new isolated high proper motion T dwarf candidates from UKIDSS DR6 and SDSS DR7
R. -D. Scholz
Aims: Completing the poorly known substellar census of the solar neighbourhood, especially with respect to the coolest brown dwarfs, will lead to a better understanding of failed s…
ULAS J141623.94134836.3 - a faint common proper motion companion of a nearby L dwarf. Serendipitous discovery of a cool brown dwarf in UKIDSS DR6
R. -D. Scholz
New near-infrared large-area sky surveys (e.g. UKIDSS, CFBDS, WISE) go deeper than 2MASS and aim at detecting brown dwarfs lurking in the Solar neighbourhood which are even fainter…
SDSS J013655.91+242546.0 - an A-type hyper-velocity star from the outskirts of the Galaxy
A. Tillich, N. Przybilla, R. -D. Scholz +1
Hyper-velocity stars (HVS) are moving so fast that they are unbound to the Galaxy. Dynamical ejection by a supermassive black hole is favoured to explain their origin. Locating the…
An extremely wide and very low-mass pair with common proper motion. Is it representative of a nearby halo stream?
R. -D. Scholz, N. V. Kharchenko, N. Lodieu +1
(abridged) We describe the discovery of an extremely wide pair of low-mass stars with a common large proper motion and discuss their possible membership in a Galactic halo stream c…
An active M8.5 dwarf wide companion to the M4/DA binary LHS4039/LHS4040
R. -D. Scholz, N. Lodieu, R. Ibata +4
Low-mass and brown dwarfs have recently been found as wide companions to many nearby stars, formerly believed to be single. Wide binaries are usually found as common proper motion…
New nearby stars selected in a high proper motion survey by DENIS photometry
C. Reyle, A. C. Robin, R. -D. Scholz +1
We present new nearby stars extracted from a proper motion catalogue and having a DENIS counterpart. Their distances and spectral type are estimated using the DENIS colours. 107 st…
Search for nearby stars among proper motion stars selected by optical-to-infrared photometry. I. Discovery of LHS 2090 at spectroscopic distance of d=6pc
R. -D. Scholz, H. Meusinger, H. Jahreiß
We present the discovery of a previously unknown very nearby star - LHS 2090 at a distance of only d=6 pc. In order to find nearby (i.e. d < 25 pc) red dwarfs, we re-identified hig…