Stella Malaroda

Frequency of Binaries in the Open Cluster Trumpler 14

We present new spectroscopic data for nine objects among the brightest stars in the field of the open cluster Trumpler 14. Radial velocities were measured from around 80 new spectrograms in order to provide more information about the binary nature of these objects. From this material, we conclude that at least two of the stars in the sample are radial-velocity variables, one of them showing double He i features.

Elemental abundance studies of CP stars The helium-weak stars HD 19400, HD 34797 and HD 35456*

An analysis of the abundances of the helium-weak CP stars HD 19400, HD 34797 and HD 35456, is presented using ATLAS9 model atmospheres and observational material taken with a REOSC echelle spectrograph attached to the Jorge Sahade 2.15 m telescope at CASLEO. The light elements are deficient except silicon which is overabundant in HD 19400 and HD 34797. The iron peak elements are all overabundant by factors between 5 and 60. The heavy elements show an overabundance in the three stars studied.

Elemental abundance study of the CP star HD 206653

An analysis of the abundances of the Silicon star HD 206653 is presented using an ATLAS9 model atmosphere and observational material taken with a REOSC echelle spectrograph attached to the Jorge Sahade 2.15 m telescope at CASLEO. The light elements are solar or deficient except silicon which is overabundant by a factor of 5. The iron peak elements are all overabundant by factors between 10 and 50. Sr and Y are around 1000 times the solar values. Among the Rare Earths only Ce and Eu are identified; both are overabundant by large factors.

Radial velocities in the open cluster Trumpler 14

In this paper we present radial velocity measurements of probable members of Trumpler 14, a very young open cluster associated with the Carina Nebula. We have found 4 double-line spectroscopic binaries and 2 single-line spectroscopic binaries. We have succeeded in deriving orbital elements for the SB1s. All the binaries are of potential astrophysical interest and are worth further observational efforts.

A Double‐lined Spectroscopic Binary in the Open Cluster Trumpler 14

We present the results of a determination of the preliminary orbital elements of the spectroscopic binary FMM 3 in the field of the open cluster Trumpler 14. The spectrum of this binary shows two sets of lines that are roughly similar. The period found was around 5 days (P = 5.0339 ± 0.0003), and the orbit is eccentric (e = 0.51 ± 0.02). These values were adopted from the combined solution for both components. The mass ratio of the system is 0.76 ± 0.06.

Elemental abundance studies using the EBASIM spectrograph of the 2.1-m CASLEO Observatory telescope. I. The normal stars 5 Aqr and 30 Peg

Using data from the new EBASIM spectrograph at the 2.1-m telescope of the Com- plejo Astronomico El Leoncito (CASLEO), two rather sharp-lined B stars 5 Aqr (=HD 198667, B9 III) and 30 Peg (=HD 211924, B5 IV) are being studied. The measurements are compared with those from the coude spectrograph of the 1.22-m telescope of the Dominion Astrophysical Observatory (DAO). The equivalent width scales of the EBASIM and the DAO data are similar. As we found that the line profiles of 30 Peg are variable, we are trying to determine whether this star is a slowly pulsating B star. 5 Aqr has abundances close to those of the Sun.

Spectral Morphology in the Open Cluster NGC 2287

As part of a long range program on spectral classification in open clusters we have obtained high quality spectrograms (39 A mm −1 and 125 A mm −1 both 1.2mm wide) of 35 stars in NGC 2287.