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Mapping the Northern Galactic Disk Warp with Classical Cepheids

Soszyński, I.; Udalski, A.; Szymański, M. K. +11 more

We present an updated three dimensional map of the Milky Way based on a sample of 2431 classical Cepheid variable stars, supplemented with about 200 newly detected classical Cepheids from the OGLE survey. The new objects were discovered as a result of a dedicated observing campaign of the ≈280 square degree extension of the OGLE footprint of the G…

K2-295 b and K2-237 b: Two Transiting Hot Jupiters

Kuzuhara, M.; Alonso, R.; Deeg, H. +32 more

We report the discovery from K2 of two transiting hot Jupiter systems. K2-295 (observed in Campaign 8) is a K5 dwarf which hosts a planet slightly smaller than Jupiter, orbiting with a period of 4.0 d. We have made an independent discovery of K2-237 b (Campaign 11), which orbits an F9 dwarf every 2.2 d and has an inflated radius 60-70% larger than…

On the Relation between Interstellar Spectral Features and Reddening

Krełowski, J.; Bondar, A.; Galazutdinov, G. +1 more

It is well known that interstellar spectral features correlate with color excess E(B-V). This suggests that measuring intensities of these features allows one to estimate reddening of stars. The aim of this paper is to check how tight intensities of interstellar diffuse bands (DIBs) are related to the amount of extinction, measured using E(B-V). <…

Hen 3-160 - the First Symbiotic Binary with Mira Variable S Star

Gromadzki, M.; Mikołajewska, J.; Iłkiewicz, K. +3 more

Hen 3-160 is reported in Belczyński et al. catalog as a symbiotic binary system with M7 giant donor. Using V- and I-band photometry collected over 20 years we have found that the giant is a Mira variable pulsating with 242.5-day period. The period-luminosity relation locates Hen 3-160 at the distance of about 9.4 kpc, and its Galactic coordinates …

CoRoT-18 b: Analysis of High-Precision Transit Light Curves with Starspot Features

Heras, A. M.; Gondoin, P.; Schmidt, T. O. B. +4 more

When a planet occults a spotty area on a stellar surface, the flux increases and a characteristic feature in a light curve - a bump - is observed. Among the planets detected by the CoRoT-mission CoRoT-18 is especially interesting as it exhibited spot crossings that we have analyzed in detail. We used four ground-based observations obtained at a 1.…

Central Wavelengths and Profile Shapes of Diffuse Interstellar Bands versus Physical Parameters of Intervening Clouds

Krełowski, J.; Galazutdinov, G. A.; Marić, T. +2 more

We investigate whether there are variations of the central wavelengths or the profile shapes of diffuse interstellar bands and whether these variations are caused by different physical parameters of translucent clouds. For this purpose we used spectra of two stars seen through two different single clouds: HD 34078 (AE Aur) and HD 73882. The wavele…

OGLE Collection of Galactic Cepheids

Soszyński, I.; Udalski, A.; Szymański, M. K. +10 more

We present here a new major part of the OGLE Collection of Variable Stars - OGLE Collection of Galactic Cepheids. The new dataset was extracted from the Galaxy Variability Survey images - a dedicated large-scale survey of the Galactic disk and outer bulge conducted by the OGLE project since 2013.

The OGLE collection contains 2721 Cepheids of …

An Almanac of Predicted Microlensing Events for the 21st Century

Nielsen, M. B.; Bramich, D. M.

Using Gaia data release 2 (GDR2), we present an almanac of 2509 predicted microlensing events, caused by 2130 unique lens stars, that will peak between July 25, 2026 and the end of the century. This work extends and completes a thorough search for future microlensing events initiated by Bramich and Nielsen using GDR2. The almanac includes 161 lens…

Predicted Microlensing Events by Nearby Very-Low-Mass Objects: Pan-STARRS DR1 vs. Gaia DR2

Nielsen, M. B.; Bramich, D. M.

Microlensing events can be used to directly measure the masses of single field stars to a precision of ≈1-10%. The majority of direct mass measurements for stellar and sub-stellar objects typically only come from observations of binary systems. Hence microlensing provides an important channel for direct mass measurements of single stars. The Gaia …

Contemporaneous Broad-Band Photometry and Hα Observations of T Tau Stars

Montes, D.; Guillout, P.; Frasca, A. +2 more

In this paper we present the results of a simultaneous BVRI and Hα photometric monitoring, contemporaneous to medium-resolution spectroscopy of six T Tau stars in the Taurus-Auriga star forming region. We have characterized the Hα photometric system using synthetic templates and the contemporaneous spectra of the targets. We show that we can achie…