Related papers: The Star Formation History and Mass Function of th…

We present uvbybeta CCD photometry of the central region of the double cluster h and chi Persei. We identify 350 stars, of which 214 were not included in Oosterhof catalogue. Our magnitude limit V=16.5 allows us to reach early F spectral…

(Abridged) From photometric observations of $\sim$ 47,000 stars and spectroscopy of $\sim$ 11,000 stars, we describe the first extensive study of the stellar population of the famous Double Cluster, h and $\chi$ Persei, down to subsolar…

We present CCD uvby-beta photometry for stars in the nuclei of the young double cluster h and chi Persei. We find that the reddening is highly variable through the h Persei nucleus, increasing from west to east, with values ranging from…

Projected rotational velocities have been measured for 216 B0--B9 stars in the rich, dense h and chi Persei double cluster, and compared with the distribution of rotational velocities for a sample of field stars having comparable ages and…

We describe Spitzer/MIPS observations of the double cluster, h and $\chi$ Persei, covering a $\sim$ 0.6 square-degree area surrounding the cores of both clusters. The data are combined with IRAC and 2MASS data to investigate $\sim$ 616…

We describe IRAC 3.6-8 mu_m observations and ground-based near-IR JHKs photometry from Mimir and 2MASS of the massive double cluster h & chi Persei complete to J=15.5 (M ~ 1.3 Msun. Within 25' of the cluster centers we detect \~11,000…

We analyze very deep IRAC and MIPS photometry of $\sim$ 12,500 members of the 14 Myr old Double Cluster, h and $\chi$ Persei, building upon on our earlier, shallower Spitzer studies (Currie et al. 2007a, 2008a). Numerous likely members show…

In order to study the stellar population and possible substructures in the outskirts of Double Cluster $h$ and $\chi$ Persei, we investigate using the GAIA DR2 data a sky area of about 7.5 degrees in radius around the Double Cluster cores.…

We present broad-band (U, V, I,and H) and narrow-band(H-alpha+[N II] and Paschen-alpha) images of the circumnuclear starburst rings in two nearby spiral galaxies, NGC 1512 and NGC 5248, obtained with WFPC2 and NICMOS on HST. Combined with…

UBVI and Ha photometry is presented for 17319 stars in vicinity of the young double cluster h & chi Persei. Our photometry extends over a 37arcmin x 1arcdeg field centered on the association. We construct reddening contours within the…

We present blue optical spectra of 92 members of h and chi Per obtained with the WIYN telescope at Kitt Peak National Observatory. From these spectra, several stellar parameters were measured for the B-type stars, including V sin i, T_eff,…

We present a study of the B and Be star populations of the Double Cluster h and chi Persei. Blue optical spectroscopy is used to first measure projected rotational velocity, V sin i, effective surface temperature, T_eff, and surface…

The Per OB1 association, which contains the remarkable double cluster h and chi Per, is unusual in not having a giant molecular cloud in its vicinity. We show from Hipparcos data that the luminous members of this association exhibits a bulk…

We describe Chandra/ACIS-I observations of the massive ~ 13--14 Myr-old cluster, h Persei, part of the famous Double Cluster (h and chi Persei) in Perseus. Combining the list of Chandra-detected sources with new optical/IR photometry and…

There is a lack of state-of-the-art information on very young open clusters, with implications for determining the structure of the Galaxy. Our main objective is to study the timing and location of the star formation processes which yielded…

The Hydra I cluster offers an excellent opportunity to study and compare the relic old stellar populations in the core of its two brightest galaxies. In addition, the differing kinematics of the two galaxies allows a test of the local…

Two hundred and forty-two members of the Praesepe and alpha Persei clusters ranging from B (~5Msun) to early-M (~0.5 Msun) have been surveyed with high angular resolution imaging. The 39 binary and 1 quadruple systems detected encompass…

We have obtained membership probabilities of stars within a field of radius $\sim3^\circ$ around the centre of the open cluster Alpha Persei using proper motions and photometry from the PPMXL and WISE catalogues. We have identified 810…

We derive absolute dimensions for two early-type main sequence detached eclipsing binaries in the young open cluster h Persei (NGC 869). V615 Persei has a spectral type of B7V and a period of 13.7d. V618 Persei is A2V and has a period of…

We analyze 8 sources with strong mid-infrared excesses in the 13 Myr-old double cluster h and chi Persei. New optical spectra and broadband SEDs (0.36-8 mu_m) are consistent with cluster membership. We show that material with T ~ 300-400 K…