Spectroscopy of QUEST RR Lyrae Variables: the new Virgo Stellar Stream

Eighteen RR Lyrae variables (RRLs) that lie in the "12\fh 4 clump" identified by the QUEST survey have been observed spectroscopically to measure their radial velocities and metal abundances. Ten blue horizontal branch (BHB) stars identified by the Sloan Digital Sky Survey (SDSS) were added to this sample. Six of the 9 stars in the densest region of the clump have a mean radial velocity in the galactic rest frame ($V_{\rm gsr}$) of 99.8 and $\sigma$ = 17.3 ${\rm km s}^{-1}$, which is slightly smaller than the average error of the measurements. The whole sample contains 8 RRLs and 5 BHB stars that have values of $V_{\rm gsr}$ suggesting membership in this stream. For 7 of these RRLs, the measurements of [Fe/H], which have an internal precision of 0.08 dex, yield $= -1.86$ and $\sigma$ = 0.40. These values suggest that the stream is a tidally disrupted dwarf spheroidal galaxy of low luminosity. Photometry from the database of the SDSS indicates that this stream covers at least 106 deg$^2$ of the sky in the constellation Virgo. The name Virgo Stellar Stream is suggested.Comment: Replaced with revised version accepted for publication in ApJ Letters 13 pages 4 figure

Basic parameters of three star clusters in the Small Magellanic Cloud: Kron 11, Kron 63 and NGC 121

We present observations for three star clusters, Kron 11, Kron 63 and NGC 121, in the Small Magellanic Cloud. We have studied their structure and derived their fundamental parameters by means of their luminosity functions, their color magnitude diagrams and the Padova suite of isochrones. NGC 121 is a well studied object, for which we confirm previous evidence about its old age and low metal content, and have found that it is undergoing mass segregation. Kron 11 and Kron 63 are poorly populated clusters which had never been studied so far. Kron 11 is several gigayears younger than NGC 121, while Kron 63 is basically a very young star aggregate. Both clusters are immersed in dense stellar fields which share the same population properties, suggesting that in their cases, cluster ages are consistent with typical ages of field stars.Comment: 9 pages; 7 figures, MNRAS pape

A cross-sectional study of cryptorchidism in children: testicular volume and hormonal function at 18 years of age

Purpose To evaluate the relationship between unilateral or bilateral criptorchidism, patient age, primary location of the gonad and modality of treatment with testicular volume and hormonal status at 18 years in patients diagnosed and treated for cryptorchidism during childhood. Materials and Methods Testicular volume, LH, FSH, and testosterone were evaluated in 143 young men at 18 years treated in childhood for unilateral (n=103) or bilateral (n=40) cryptorchidism. Results Unilateral cryptorchidism: Location of testis was prescrotal in 36 patients, inguinal in 52 and non-palpable in 15. The mean volume was 9.7 mL compared to 16.2 mL. for the spontaneously descended testicle in unilateral cryptorchidism. However, 22 patients who received HCG had a significantly bigger testis (11.8 mL.) than those treated with primary surgery (9.2 mL). The results showed a significant positive correlation between testicular volume and patient age at treatment. Bilateral cryptorchidism Location of testis was prescrotal in 34 cases, inguinal in 40 and 6 patients with non-palpable testicles. Mean volume at 18 years was 12.9 mL, greater than unilateral cryptorchid testis (9.7 mL) but smaller than healthy contralateral in unilateral cases (16.2 mL). There were significant differences in the testicular growth for bilateral patients with testicular descent after being treated with HCG (14.4 mL) in respect with those untreated (11.1 mL) or those who underwent primary surgery (11.4 mL). There was a significant positive correlation between the testicular volume and palpable (12.4 mL) or non-palpable testis (10.4 mL). There was a correlation between unilateral or bilateral cryptorchidism and levels of FSH. Conclusions Testicular volume and hormonal function at 18 years for patients diagnosed and treated for cryptorchidism during childhood are strongly influenced by whether the undescended testis was unilateral or bilateral. Location of the testes at diagnosis or age of initial treatment exerts no definite effect on testicular volume improvement or hormonal levels at 18 years of age