Mercator and the P7-2000 photometer

Raskin, Gert; Burki, G.; Burnet, M.; Davignon, G.; Dubosson, Rene; Ischi, E.; George, Michel; Grenon, M.; Maire, C.; Winckel, H. Van; Waelkens, Christoffel; Weber, L.

doi:10.1117/12.550191

Cited by 13 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…-Station 37 -La Palma: these all-sky seven-colour (7-C) observations were secured in the Geneva photometric system using the two-channel aperture photometer P7-2000 (Raskin et al 2004) mounted on the 1.20 m Belgian Mercator reflector at the Observatorio de los Muchachos at La Palma. -Station 61 -Hipparcos: these all-sky observations were reduced to the standard V magnitude via the transformation formulae derived by to verify that no secular light changes in the system were observed.…”

Section: Appendix B: Details On the Photometric Data Reductionsmentioning

confidence: 99%

Properties and nature of Be stars

Harmanec

Koubský

Nemravová

et al. 2015

A&A

View full text Add to dashboard Cite

Reliable determination of the basic physical properties of hot emission-line binaries with Roche-lobe filling secondaries is important for developing the theory of mass exchange in binaries. It is a very hard task, however, which is complicated by the presence of circumstellar matter in these systems. So far, only a small number of systems with accurate values of component masses, radii, and other properties are known. Here, we report the first detailed study of a new representative of this class of binaries, BR CMi, based on the analysis of radial velocities and multichannel photometry from several observatories, and compare its physical properties with those for other well-studied systems. BR CMi is an ellipsoidal variable seen under an intermediate orbital inclination of ∼51• , and it has an orbital period of 12.d 919059(15) and a circular orbit. We used the disentangled component spectra to estimate the effective temperatures 9500(200) K and 4655(50) K by comparing them with model spectra. They correspond to spectral types B9.5e and G8III. We also used the disentangled spectra of both binary components as templates for the 2D cross-correlation to obtain accurate radial velocities and a reliable orbital solution. Some evidence of a secular period increase at a rate of (1.1 ± 0.5) s per year was found. This, together with a very low mass ratio of 0.06 and a normal mass and radius of the mass gaining component, indicates that BR CMi is in a slow phase of the mass exchange after the mass-ratio reversal. It thus belongs to a still poorly populated subgroup of Be stars for which the origin of Balmer emission lines is safely explained as a consequence of mass transfer between the binary components.

show abstract

Section: Appendix B: Details On the Photometric Data Reductionsmentioning

confidence: 99%

Properties and nature of Be stars

Harmanec

Koubský

Nemravová

et al. 2015

A&A

View full text Add to dashboard Cite

show abstract

“…The stars accessible from La Palma were included in the long-term photometric monitoring programme performed with the 1.2 m Mercator telescope using the refurbished Geneva 7-band dual-beam photometer (Raskin et al 2004). This resulted in 47 high quality absolute photometric measurements for IRAS 19125+0343, but only 6 for IRAS 19157-0247.…”

Section: Data and Data Reductionmentioning

confidence: 99%

Post-AGB stars with hot circumstellar dust: binarity of the low-amplitude pulsators

Winckel¹,

Evans

Briquet³

et al. 2009

A&A

138

141

View full text Add to dashboard Cite

Context. The influence of binarity on the late stages of stellar evolution remains an open issue. Aims. While the first binary post-AGB stars were serendipitously discovered, the distinct characteristics of their spectral energy distribution (SED) allowed us to launch a more systematic search for binaries. We selected post-AGB objects, which exhibit a broad dust excess starting either at H or K, pointing to the presence of a gravitationally bound dusty disc in the system. We initiated an extensive multiwavelength study of those systems and here report on our radial velocity and photometric monitoring results for six stars of early F type, which are pulsators of small amplitude. Methods. To determine the radial velocity of low signal-to-noise ratio time-series data, we constructed dedicated autocorrelation masks based on high signal-to-noise ratio spectra, used in our published chemical studies. The radial velocity variations were analysed in detail to differentiate between pulsational variability and variability caused by orbital motion. When available, the photometric monitoring data were used to complement the time series of radial velocity data and to establish the nature of the pulsation. Finally, orbital minimalisation was performed to constrain the orbital elements. Results. All of the six objects are binaries with orbital periods ranging from 120 to 1800 days. Five systems have non-circular orbits. The mass functions range from 0.004 to 0.57 M and the companions are probably unevolved objects of (very) low initial mass. We argue that these binaries must have evolved through a phase of strong binary interaction when the primary was a cool supergiant. Although the origin of the circumstellar disc is not well understood, the disc is generally believed to have formed during this strong interaction phase. The eccentric orbits of these highly evolved objects remain poorly understood. In one object, the line-of-sight grazes the edge of the puffed-up inner rim of the disc. Conclusions. These results corroborate our earlier statement that evolved objects in binary stars create a Keplerian dusty circumbinary disc. With the measured orbits and mass functions, we conclude that the circumbinary discs seem to have a major impact on the evolution of a significant fraction of binary systems. Tables 4-6 are only available in electronic form at

show abstract

“…NGC 6778 was observed for a continuous 6.35 h on 19 June 2010 with the MEROPE camera (Davignon et al 2004) on the Flemish 1.2 m Mercator telescope (Raskin et al 2004). A Geneva G filter (λ eff = 576.59 nm, W 0 = 22.18 nm) was used to help minimise the nebula contamination.…”

Section: Lightcurves Of Ngc 6326 and Ngc 6778mentioning

confidence: 99%

Discovery of close binary central stars in the planetary nebulae NGC 6326 and NGC 6778

Miszalski

Jones

Rodríguez‐Gil

et al. 2011

A&A

View full text Add to dashboard Cite

We present observations proving the close binary nature of the central stars belonging to the planetary nebulae (PNe) NGC 6326 and NGC 6778. Photometric monitoring reveals irradiated lightcurves with orbital periods of 0.372 and 0.1534 days, respectively, constituting firm evidence that they passed through a common-envelope (CE) phase. Unlike most surveys for close binary central stars (CSPN) however, the binary nature of NGC 6326 was first revealed spectroscopically and only later did photometry obtain an orbital period. Gemini South observations revealed a large 160 km s −1 shift between the nebula and emission lines of C III and N III well known to originate from irradiated atmospheres of main-sequence companions. These so-called weak emission lines are fairly common in PNe and measurement of their radial velocity shifts in spectroscopic surveys could facilitate the construction of a statistically significant sample of post-CE nebulae. There is growing evidence that this process can be further accelerated by preselecting nebulae with traits of known post-CE nebulae. Both NGC 6326 and NGC 6778 were selected for their rich attribution of low-ionisation filaments and collimated outflows, thereby strengthening the connection between these traits and post-CE CSPN.

show abstract

Mercator and the P7-2000 photometer

Cited by 13 publications

References 0 publications

Properties and nature of Be stars

Properties and nature of Be stars

Post-AGB stars with hot circumstellar dust: binarity of the low-amplitude pulsators

Discovery of close binary central stars in the planetary nebulae NGC 6326 and NGC 6778

Contact Info

Product

Resources

About