相关论文: Herbig Ae/Be candidate stars in the innermost Gala…

We have carried out a study of the early type stars in nearby OB associations spanning an age range of $\sim$ 3 to 16 Myr, with the aim of determining the fraction of stars which belong to the Herbig Ae/Be class. We studied the B, A, and F…

We derived the intermediate-mass (~=1.5--7 M_sun) disk fraction (IMDF) in the near-infrared JHK photometric bands as well as in the mid-infrared (MIR) bands for young clusters in the age range of 0 to ~10 Myr. From the JHK IMDF, the…

Using UBVRI Halpha CCD photometric observations and the archival NIR and X-ray data, we have carried out a multi-wavelength study of a young star cluster NGC 7419. An age of 22.5+/-3.0 Myr and a distance of 3230^{+330}_{-430} pc are derived…

The recent findings of gas giant planets around young A-type stars suggest that disks surrounding Herbig Ae/Be stars will develop planetary systems. An interesting case is HD142527, for which previous observations revealed a complex…

We present NIR and MIR observations of eight embedded young stellar groups around Herbig Ae/Be stars (HAEBEs) using archived Spitzer IRAC data and 2MASS data. These young stellar groups are nearby ($\leq$ 1 kpc) and still embedded within…

We present optical spectra of four intermediate mass candidate young stellar objects that have often been classified as Herbig Ae/Be stars. Typical Herbig Ae/Be emission features are not present in the spectra of these stars. Three of them,…

We present a study of the star cluster population in the starburst irregular galaxy NGC 4449 based on B, V, I, and Ha images taken with the Advanced Camera for Surveys on the Hubble Space Telescope. We derive the cluster properties such as…

We have carried out a survey of compact star clusters (apparent size <3 arcsec) in the southwest part of the M31 galaxy, based on the high-resolution Suprime-Cam images (17.5 arcmin x 28.5 arcmin), covering ~15% of the deprojected galaxy…

The accretion of material from protoplanetary disks onto their central stars is a fundamental process in the evolution of these systems and a key diagnostic in constraining the disk lifetime. We analyze the relationship between the stellar…

We present the results of a survey of young intermediate mass stars (age $<$~5 Myr, 1.5 $<M_{\star} \leq $ 15 $M_{\odot}$) in the W5 massive star forming region. We use combined optical, near-infrared and {\it Spitzer} Space Telescope…

The large body of near infrared observations presented in Testi et al. (1997; 1998) are analysed with the aim of characterizing the young stellar clusters surrounding Herbig Ae/Be stars. The results confirm the tendency of early Be stars to…

With the KOSMA 3-m telescope, 54 Herbig Ae/Be stars were surveyed in CO and $^{13}$CO emission lines. The properties of the stars and their circumstellar environments are studied by fitting the SEDs. The mean line width of $^{13}$CO (2-1)…

We seek to find the precursors of the Herbig Ae/Be stars in the solar vicinity within 500 pc from the Sun. We do this by creating an optically selected sample of intermediate mass T-Tauri stars (IMTT stars) here defined as stars of masses…

We present the results of an infrared photometric survey performed with NICS@TNG in the nearby starburst galaxy NGC 4214. We derived accurate integrated JK magnitudes of 10 young massive clusters and compared them with the already available…

Disclosing the structure of disks surrounding Herbig AeBe stars is important to expand our understanding of the formation and early evolution of stars and planets. We aim at revealing the sub-AU disk structure around the 10 Myr old Herbig…

We report the results of a sensitive K-band survey of Herbig Ae/Be disk sizes using the 85-m baseline Keck Interferometer. Targets were chosen to span the maximum range of stellar properties to probe the disk size dependence on luminosity…

We analyse a sample of 507 evolved stars in the inner galactic Plane. We derive average ages for subsets of this sample and use those sets as beacons for the evolution of the Galaxy. In the Bulge the oldest OH/IR stars in the plane are 7.5…

Planet formation has been known for many years to be tied to the spatial distribution of gas and dust in disks around young stars. To constrain planet formation models, imaging observations of protoplanetary disks are required. In this…

We report new Spitzer observations of intermediate mass stars in two regions of the Orion OB1 association located in the subassociations OB1a ($\sim$10 Myr) and OB1b ($\sim$5 Myr). In a representative sample of stars earlier than F5 of both…

We present a multi-wavelength photometric and spectroscopic study of a newly discovered candidate cluster [DBS2003] 45. Our H, Ks photometry confirms that [DBS2003] 45 is a cluster. An average visual extinction Av 7.1+/-0.5 is needed to fit…