... dwarf

Based on observations made with the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.

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...

Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Centro Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.

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... images

Taken with the NICS camera on the 3.6-m TNG telescope on La Palma.

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... temperatures

This temperature seems to be the lower limit for DQ stars, and might be associated with the transition of C₂ into C₂H molecules (Bergeron et al. 2001).

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... components

Assuming a solar motion of $U_\odot=10.00$ km s^-1 and $V_\odot=5.25$ km s^-1, as from Dehnen & Binney (1998). The (U,V) components are computed from $\mu_{\alpha}\cos\delta$, $\mu_{\delta}$ only. However, given the high galactic latitude of this star ( $b \simeq 85^\circ$), the unknown V_r component would contribute less than 4% and 7.6% to the U and V values, respectively.

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... population

Here, we have adopted the velocity ellipsoids $(\sigma_U,~ \sigma_V,~ \sigma_W;~ v_a)=(34, 21, 18; 6)$ km s^-1 and (61, 58, 39; 36) km s^-1 for the thin and thick disk respectively (Table 10.4 of Binney & Merrifield 1998). The halo ellipsoid $(\sigma_U,~ \sigma_V,~ \sigma_W;~ v_a)=(160, 89, 94; 217)$ km s^-1 is from Casertano et al. (1990). Note that these kinematics parameters are still not well established. In particular the estimated (U,V) components would result consistent with the halo kinematics, but only marginally with the thick disk parameters, recently derived by Chiba & Beers (2000).

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