All Figures

$\begin{figure} \mbox{\includegraphics[width=4.4cm]{2610f1.eps}\hspace*{1mm} \inc... ...10f3.eps}\hspace*{1mm} \includegraphics[width=4.4cm]{2610f4.eps} }\end{figure}$ Figure 1: $10\hbox {$^\prime $ }\times 10\hbox {$^\prime $ }$ finding charts for HS 0139+0559, HS 0229+8016, HS 0506+7725, and HS 0642+5049 obtained from the Digitized Sky Survey. The J2000 coordinates of the CVs are ( $\alpha =01^{\rm h}41^{\rm m}40.0^{\rm s}$ , $\delta =+06\hbox {$^\circ $ }14\hbox {$^\prime $ }36.8\hbox {$^{\prime \prime }$ }$ ), ( $\alpha =02^{\rm h}35^{\rm m}58.3^{\rm s}$ , $\delta =+80\hbox {$^\circ $ }29\hbox {$^\prime $ }44.0\hbox {$^{\prime \prime }$ }$ ), ( $\alpha =05^{\rm h}13^{\rm m}36.4^{\rm s}$ , $\delta =+77\hbox {$^\circ $ }28\hbox {$^\prime $ }42.1\hbox {$^{\prime \prime }$ }$ ), and ( $\alpha =06^{\rm h}46^{\rm m}19.60^{\rm s}$ , $\delta =+50\hbox {$^\circ $ }45\hbox {$^\prime $ }48.0\hbox {$^{\prime \prime }$ }$ ), respectively.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f5.ps} }\end{figure}$ Figure 2: Identification spectrum of HS 0139+0559 obtained at the Calar Alto 3.5 m telescope on January 22, 1989.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8.2cm,clip]{2610f6.ps} }\end{figure}$ Figure 3: Identification spectra of HS 0229+8016 obtained at the Calar Alto 2.2 m telescope on August 8, 1992 ( top panel) and February 2, 1998 ( bottom panel).
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f7.ps} }\end{figure}$ Figure 4: Identification spectrum of HS 0506+7725 obtained at the Calar Alto 2.2 m telescope on February 2, 1998.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f8.ps} }\end{figure}$ Figure 5: Average of the 17 CAFOS G-100 spectra of HS 0642+5049 obtained at the Calar Alto 2.2 m telescope on October 24, 2004.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f9.ps} }\end{figure}$ Figure 6: Differential CCD R-band ( top panel) and B-band ( bottom panel) photometry of HS 0139+0559 obtained at the Braeside observatory.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f10.ps} }\end{figure}$ Figure 7: Sample light curves of HS 0229+8016. Top panel: R-band data obtained at the Kryoneri observatory. Bottom panel: filterless data obtained at the Tuorla observatory.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f11.ps} }\end{figure}$ Figure 8: Sample light curves of HS 0506+7725. Top panel: R-band data obtained at the Kryoneri observatory. Bottom panel: filterless data obtained at the OGS telescope.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f12.ps} }\end{figure}$ Figure 9: Sample filterless light curves of HS 0642+5049 obtained at the IAC80 telescope.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8.8cm]{2610f13.ps} }\end{figure}$ Figure 10: The Scargle periodogram of the radial velocities of HS 0139+0559 measured from the $\mbox{${\rm H\alpha}$ }$ emission line. The periodogram from a set of fake radial velocities is shown in the top panel.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8.8cm]{2610f14.ps} }\end{figure}$ Figure 11: The Scargle periodogram of the radial velocities of HS 0229+8016 measured from the $\mbox{${\rm H\alpha}$ }$ emission line. The periodogram from a set of fake radial velocities is shown in the top panel.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8.8cm]{2610f15.ps} }\end{figure}$ Figure 12: The Scargle periodogram of the radial velocities of HS 0506+7725 measured from the $\mbox{${\rm H\alpha}$ }$ emission line by using the double Gaussian method. The periodogram from a set of fake radial velocities is shown in the top panel.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8.8cm]{2610f16.ps} }\end{figure}$ Figure 13: The Scargle periodogram of HS 0642+5049 computed from the three longest nights of differential photometry obtained at the Calar Alto (October 25, 2004) and the IAC80 (December 8 and 9, 2004). The periodogram from a fake data set assuming a period of 225.90 min is shown in the top panel.
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In the text

$\begin{figure} {\includegraphics[width=8.2cm,clip]{2610f17.ps} }\end{figure}$ Figure 14: $\mbox{${\rm H\alpha}$ }$ radial velocities of HS 0139+0559 ( top panel), HS 0229+8016 ( middle panel), and HS 0506+7725 ( bottom panel) folded on the period of 243.69 min, 232.550 min, and 212.7 min, respectively. The dashed lines are the best sine fits to the folded velocities.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8.8cm]{2610f18.ps} }\end{figure}$ Figure 15: HS 0642+5049 photometric data from the CAFOS (October 9, 2004) and the IAC80 (December 8 and 9, 2004) folded on $\mbox{$P_{\rm orb}$ }=225.90$ min ( top panel). The average light curve, binned into 30 phase, is shown in the bottom panel along with a sine fit (dashed line).
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8.2cm,clip]{2610f19.ps} }\end{figure}$ Figure 16: The period distribution of 42 new CVs discovered in the HQS ( left panel) and of all known CVs ( right panel, from Ritter & Kolb 2003, V7.4). The 2-3 h period gap is shaded in gray.
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8.2cm,clip]{2610f20.ps} }\end{figure}$ Figure 17: The period distribution of the individual CV subtypes in the 3-4 h period range. From top to bottom: polars (am), intermediate polars (ip), VY Scl and SW Sex stars (vy), novalike variables and nova remnants that are neither VY Scl nor SW Sex stars (nl), U Gem type dwarf novae (ug), Z Cam type dwarf novae (zc), SU UMa type dwarf novae (su), and systems with undetermined CV subtype (xx).
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In the text

$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f5.ps} }\end{figure}$	Figure 2: Identification spectrum of HS 0139+0559 obtained at the Calar Alto 3.5 m telescope on January 22, 1989.
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$\begin{figure} {\includegraphics[angle=-90,width=8.2cm,clip]{2610f6.ps} }\end{figure}$	Figure 3: Identification spectra of HS 0229+8016 obtained at the Calar Alto 2.2 m telescope on August 8, 1992 ( top panel) and February 2, 1998 ( bottom panel).
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$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f7.ps} }\end{figure}$	Figure 4: Identification spectrum of HS 0506+7725 obtained at the Calar Alto 2.2 m telescope on February 2, 1998.
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$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f8.ps} }\end{figure}$	Figure 5: Average of the 17 CAFOS G-100 spectra of HS 0642+5049 obtained at the Calar Alto 2.2 m telescope on October 24, 2004.
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$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f9.ps} }\end{figure}$	Figure 6: Differential CCD R-band ( top panel) and B-band ( bottom panel) photometry of HS 0139+0559 obtained at the Braeside observatory.
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$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f10.ps} }\end{figure}$	Figure 7: Sample light curves of HS 0229+8016. Top panel: R-band data obtained at the Kryoneri observatory. Bottom panel: filterless data obtained at the Tuorla observatory.
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$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f11.ps} }\end{figure}$	Figure 8: Sample light curves of HS 0506+7725. Top panel: R-band data obtained at the Kryoneri observatory. Bottom panel: filterless data obtained at the OGS telescope.
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$\begin{figure} {\includegraphics[angle=-90,width=8cm,clip]{2610f12.ps} }\end{figure}$	Figure 9: Sample filterless light curves of HS 0642+5049 obtained at the IAC80 telescope.
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$\begin{figure} {\includegraphics[angle=-90,width=8.8cm]{2610f13.ps} }\end{figure}$	Figure 10: The Scargle periodogram of the radial velocities of HS 0139+0559 measured from the $\mbox{${\rm H\alpha}$ }$ emission line. The periodogram from a set of fake radial velocities is shown in the top panel.
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$\begin{figure} {\includegraphics[angle=-90,width=8.8cm]{2610f14.ps} }\end{figure}$	Figure 11: The Scargle periodogram of the radial velocities of HS 0229+8016 measured from the $\mbox{${\rm H\alpha}$ }$ emission line. The periodogram from a set of fake radial velocities is shown in the top panel.
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$\begin{figure} {\includegraphics[angle=-90,width=8.8cm]{2610f15.ps} }\end{figure}$	Figure 12: The Scargle periodogram of the radial velocities of HS 0506+7725 measured from the $\mbox{${\rm H\alpha}$ }$ emission line by using the double Gaussian method. The periodogram from a set of fake radial velocities is shown in the top panel.
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$\begin{figure} {\includegraphics[angle=-90,width=8.8cm]{2610f16.ps} }\end{figure}$	Figure 13: The Scargle periodogram of HS 0642+5049 computed from the three longest nights of differential photometry obtained at the Calar Alto (October 25, 2004) and the IAC80 (December 8 and 9, 2004). The periodogram from a fake data set assuming a period of 225.90 min is shown in the top panel.
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$\begin{figure} {\includegraphics[width=8.2cm,clip]{2610f17.ps} }\end{figure}$	Figure 14: $\mbox{${\rm H\alpha}$ }$ radial velocities of HS 0139+0559 ( top panel), HS 0229+8016 ( middle panel), and HS 0506+7725 ( bottom panel) folded on the period of 243.69 min, 232.550 min, and 212.7 min, respectively. The dashed lines are the best sine fits to the folded velocities.
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$\begin{figure} {\includegraphics[angle=-90,width=8.8cm]{2610f18.ps} }\end{figure}$	Figure 15: HS 0642+5049 photometric data from the CAFOS (October 9, 2004) and the IAC80 (December 8 and 9, 2004) folded on $\mbox{$P_{\rm orb}$ }=225.90$ min ( top panel). The average light curve, binned into 30 phase, is shown in the bottom panel along with a sine fit (dashed line).
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$\begin{figure} {\includegraphics[angle=-90,width=8.2cm,clip]{2610f19.ps} }\end{figure}$	Figure 16: The period distribution of 42 new CVs discovered in the HQS ( left panel) and of all known CVs ( right panel, from Ritter & Kolb 2003, V7.4). The 2-3 h period gap is shaded in gray.
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