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Two newly identified eclipsing binaries in open cluster NGC 3532
Özdarcan, O.
We present light-curve analyses of two newly identified detached eclipsing binaries, namely HD 96609 and HD 303734, in the region of the richly populated open cluster NGC 3532. HD 96609 is composed of two main sequence stars (B9-A0V + A2V) with masses and radii of M1 = 2.66 ± 0.02 M⊙, M2 = 1.84 ± 0.01 M⊙…
Adjusting the bow-tie: a morpho-kinematic study of NGC 40
López, J. A.; Estrada-Dorado, S.; Guerrero, M. A. +4 more
We present a comprehensive study of the ionization structure and kinematics of the planetary nebula (PN) NGC 40 (a.k.a. the Bow-tie Nebula). A set of narrow-band images obtained with the Alhambra Faint Object Spectrograph and Camera at the Nordic Optical Telescope are used to study the turbulent distribution of gas in the main cavity, the ionizati…
Discovery of a Short Period Pulsator from Istanbul University Observatory
Güver, Tolga; Sağlam, Mustafa Turan; Çördük, Meryem +8 more
We report the discovery of a new short period pulsating variable in the field of exoplanet host star XO-2. Variable has been identified while it was being used as a comparison. In order to verify the variability of the candidate, a comprehensive follow-up was carried out. Period analysis of multi-band light curves revealed a very prominent and con…
Chemical Abundances of Eight Highly-extincted Milky Way Planetary Nebulae
Dinerstein, Harriet L.; Zeimann, Greg; Sterling, N. C. +1 more
Low- and intermediate-mass (0.8 M ⊙ < M < 8 M ⊙) stars that evolve into planetary nebulae (PNe) play an important role in tracing and driving Galactic chemical evolution. Spectroscopy of PNe enables access to both the initial composition of their progenitor stars and products of their internal nucleosynthesis, but deter…
Analysis of Gaia radial-velocity standards: stability and new substellar companion candidates
Gosset, E.; Damerdji, Y.; Morel, T. +4 more
Our main aim is to test the non-variability of the radial velocity (RV) of a sample of 2351 standard stars used for wavelength calibration of the Radial Velocity Spectrometer (RVS) instrument onboard Gaia. In this paper, we present the spectroscopic analysis of these stars with the determination of their physical parameters by matching observed an…
Improving INTEGRAL/SPI data analysis of GRBs
Greiner, Jochen; Siegert, Thomas; Biltzinger, Björn +1 more
The spectrometer on the international gamma-ray astrophysics laboratory (INTEGRAL/SPI) is a coded mask instrument observing since 2002 in the keV to MeV energy range, which covers the peak of the νFν spectrum of most gamma-ray bursts (GRBs). Since its launch in 2008, the gamma-ray burst monitor (GBM) on board the Fermi satellite has been the prima…
The Electric Field outward of Saturn's Main Rings
Krupp, N.; Roussos, E.; Paranicas, C. +5 more
Cassini data are consistent with a global electric field in Saturn's magnetosphere that points approximately antisunward. The inner radial extent of this field was initially established using Saturn orbit insertion data but measurements of ultrarelativistic electrons from that pass cast some doubt on whether the electric field reaches all the way …
Understanding the evolution of radiation damage on the Gaia CCDs after 72 months at L2
Seabroke, George; Ahmed, Saad; Holland, Andrew +5 more
The European Space Agency's Gaia spacecraft has been operating in L2 ever since its launch in December 2013 with a payload that includes 106 scientific charge-coupled devices (CCDs). Due to the predicted radiation environment at the pre-flight testing stage in addition to the high level of accuracy demanded by the science objectives, the non-ioniz…
Scaling properties of magnetic field fluctuations in the quiet Sun
Giannattasio, F.; Berrilli, F.; Consolini, G. +1 more
Context. The study of the dynamic properties of small-scale magnetic fields in the quiet photosphere is important for several reasons: (i) it allows us to characterise the dynamic regime of the magnetic field and points out some aspects that play a key role in turbulent convection processes; (ii) it provides details of the processes and the spatia…
The past decade of ZERODUR glass-ceramics in space applications
Krieg, Janina; Carré, Antoine; Döhring, Thorsten +4 more
For the past four decades, ZERODUR® glass ceramics has flown on many satellites including the prominent space missions METEOSAT, Hubble Space Telescope, CHANDRA, and LISA pathfinder. Firstly, this unique material is chosen as mirror substrate for high precision optics due to its extreme thermal stability. Its near-zero thermal expansion over a wid…