Chronotype and time-of-day effects on mood during school day

Existing evidence suggests an association between mood, time-of-day and Morningness-Eveningness (M-E). Since few studies have been carried out among adolescents, in this study daily mood fluctuations were analyzed in the naturalistic school context during two days in order to test how chronotype and time-of-day are related to mood during the school schedule period and check if sleep length is involved in the above relation. A sample of 655 adolescents (12-16 years) reported mood levels (current level of pleasantness) three times during school day (8:10-8:30 h, 10:20-11:40 h, 13:50-14:10 h). They also reported M-E preference and time in bed. Neither age nor sex was related to mood. However, the results indicated that regardless of chronotype mood increased throughout the school day from the lowest morning levels. Moreover, morning types showed better mood compared to other chronotypes, while evening types exhibited the lowest mood. Evening oriented students slept less than other chronotypes, but time in bed was not involved in the relationship between chronotype and mood. These results suggest that it is not shortened sleep duration responsible for decreased mood in evening oriented students.

The first extrasolar planet discovered with a new-generation high-throughput Doppler instrument

We report the detection of the first extrasolar planet, ET-1 (HD 102195b), using the Exoplanet Tracker (ET), a new-generation Doppler instrument. The planet orbits HD 102195, a young star with solar metallicity that may be part of the local association. The planet imparts radial velocity variability to the star with a semiamplitude of 63.4 ± 2.0 m s^-1 and a period of 4.11 days. The planetary minimum mass (m sin i) is 0.488MJ ± 0.015M_J. The planet was initially detected in the spring of 2005 with the Kitt Peak National Observatory (KPNO) 0.9 m coudé feed telescope. The detection was confirmed by radial velocity observations with the ET at the KPNO 2.1 m telescope and also at the 9 m Hobby-Eberly Telescope (HET) with its High Resolution Spectrograph. This planetary discovery with a 0.9 m telescope around a V = 8.05 magnitude star was made possible by the high throughput of the instrument: 49% measured from the fiber output to the detector. The ET's interferometer-based approach is an effective method for planet detection. In addition, the ET concept is adaptable to multiple-object Doppler observations or very high precision observations with a cross-dispersed echelle spectrograph to separate stellar fringes over a broad wavelength band. In addition to spectroscopic observations of HD 102195, we obtained brightness measurements with one of the automated photometric telescopes at Fairborn Observatory. Those observations reveal that HD 102195 is a spotted variable star with an amplitude of ~0.015 mag and a 12.3 ± 0.3 day period. This is consistent with spectroscopically observed Ca II H and K emission levels and line-broadening measurements but inconsistent with rotational modulation of surface activity as the cause of the radial velocity variability. Our photometric observations rule out transits of the planetary companion.