Are CV Secondaries Normal? Deconvolving the Evolutionary History of Cataclysmic Variables We present the results of VLT ISAAC K-band spectroscopy of several short period cataclysmic variable (CV) systems: EX Hya, WX Hyi, V2051 Oph, and Z Cha. Recent studies of CV secondaries in the infrared has cast doubt on the standard paradigm of CV evolution, raising important concerns specifically about the evolution of the secondary star and its initial mass. Previous infrared spectroscopic surveys of CVs above the 2 to 3 hour "period gap" reveal that these secondaries suffer a universal deficit of C12, enhanced levels of C13, and unusual abundance patterns for other species (e.g., Mg,Si, Al, Ca). Previous infrared spectroscopy of short period magnetic CVs (polars) have shown that their secondary stars appear completely normal, and the secondaries in a sample of "pre-CVs" have normal carbon abundances. To further understand the evolutionary history of CVs requires spectroscopy of short period, non-magnetic CVs, which we present in this work. It is extremely difficult to see the secondary stars in short period systems - the low luminosity secondaries are swamped by the accretion disks in these objects. But by the use of the VLT ISAAC, we have pierced the veil of the short period CVs and present firm detections of the the secondaries in these systems. Implications for CV evolution and formation scenarios will be discussed. Deconvolving the Evolutionary History of Cataclysmic Variables Cataclysmic variables are interacting binaries where one component is a white dwarf, and the other a low mass star. The standard paradigm for the evolution of these systems starts with a wide binary ($\sim$ AU) with an intermediate mass primary, and a low mass secondary star. As the primary evolves off of the main sequence, a common envelope binary is formed, and the orbit shrinks due to the loss of orbital angular momentum produced by the interaction of the secondary star with the red giant's atmosphere. Eventually a contact binary is formed, mass transfer ensues, and a cataclysmic variable (CV) is born. The secondary star should escape this process more or less unscathed, and appear $relatively$ normal. To remain in contact while losing mass, the system must shed angular momentum. It is believed that this is accomplished through the process of ``magnetic braking''. The secondary star is rotationally phase-locked to the primary, and its outflowing stellar wind sheds angular momentum as it is constrained by the secondary's magnetic field. As the mass transfer continues, the secondary star is slowly whittled-away to the point that it becomes fully convective and can no longer support a dynamo. At this point, the magnetic breaking must cease, the secondary star shrinks, and mass transfer stops. This is the standard explanation for the ``CV period gap'', the lack of CVs with orbital periods between 2 and 3 hours. But recent observations have cast doubt on this picture. An infrared spectroscopic survey of CVs above the period gap (Harrison et al. 2004, 2005a) reveals that they suffer a universal deficit of $^{\rm 12}$C, enhanced levels of $^{\rm 13}$C, and unusual abundance patterns for other species (e.g., Mg, Si, Al, Ca). There are three explanations for this: 1) during the common envelope stage the secondary star was polluted by material accreted from the red giant primary, 2) classical novae eruptions (thermonuclear runaways on the white dwarf) have deposited material on the secondary star, or 3) the initial masses of CV secondaries are higher than proposed in the standard paradigm, and we are simply seeing the CNO-processed cores of evolved, more massive stars. Which of these is correct? Surprisingly, the answer came from a similar study of magnetic CV systems (``polars''). Polars have highly magnetic white dwarfs, with field strengths in excess of 8 MG. Their evolutionary history is believed to be identical to non-magnetic CVs, as the separation during the pre-CV phase is large enough that the secondary star's magnetic moment is as large, or larger than that induced by the primary. Both magnetic and non-magnetic CVs must pass through a common envelope phase, and undergo classical novae eruptions (c.f., V1500 Cyg). Yet infrared spectroscopy (see Fig. 1) has revealed that the secondary stars of polars {\it are completely normal} (Harrison et al. 2005b). This shows that neither the common envelope phase, nor classical novae eruptions alter the secondary stars of CVs. We conclude that the initial masses of CV secondaries are higher than envisioned under the standard evolutionary paradigm. The main problem with these studies is that they sample CVs with different orbital periods: the non-magnetic CVs are of long period (P$_{\rm orb}$ $\geq$ 4 hrs), and the polars are all of short period (P$_{\rm orb}$ $\leq$ 3 hrs). This allows the possibility that they are not drawn from the same parent population (``two stream'' evolution). To further confuse the picture, Tappert et al. (2007) have shown that the secondaries in a sample of ``pre-CVs'' have normal carbon abundances. To further understand the evolutionary history of CVs requires spectroscopy of short period, non-magnetic CVs. But it is extremely difficult to see the secondary stars in short period systems--the low luminosity secondaries are swamped by the accretion disks in these objects. However, as shown in Fig. 1, even a modest increase in spectral resolution allows us to begin to pierce the veil of the accretion disk emission in short period systems. We propose to use ISAAC to obtain moderate resolution (R $\sim$ 6000) $K$-band spectroscopy of a small sample of the brightest short period CVs. This resolution will allow us to firmly detect the secondaries in these systems. [something about needing the VLT here since the targets are faint, and mostly southern?] Harrison, T. E., et al. 2004, AJ, 127, 3493 Harrison, T. E., et al. 2005a, AJ, 129, 2400 Harrison, T. E., et al. 2005b, ApJ, 632, L123 Tappert, C., et al. 2007, astro-ph/0707.0501 Possible Targets: Name RA Dec P_orb K notes VW Hyi 04:09:11.3 -71:17:41 0.074 11.75 V1159 Ori 05:28:59.5 -03:33:53 0.062 13.68 YZ Cnc 08:10:56.6 +28:08:34 0.087 12.84 (weak ellipsoidals seen) OY Car 10:06:22.1 -70:14:04 0.063 13.50 (secondary star 50\% @ K?) EX Hya 12:52:24.4 -29:14:57 0.068 11.71 (secondary star in Fig 1) V893 Sco 16:15:15.1 -28:37:31 0.076 12.66 Accreting close binaries containing a highly magnetic white dwarf, termed polars, can sometimes undergo prolonged periods of low accretion rates. The optical fluxes of such low-state polars are dimmer by several magnitudes; however, excess emission over that from the bare white dwarf and late type secondary is still typically seen from the IR to the X-ray. This excess emission has been successfully modeled by hot spots (10^4-10^5 K) near the white dwarf's magnetic poles in high states. In this poster, we present GALEX near and far ultraviolet light curves of 2 polars (EF ERI and SDSSJ155331+5516) taken during extremely low accretion rate stages. These UV data (supplemented with optical light curves) place strong constraints on the physical properties of EF ERI and SDSS1553. We discuss our results from hot spot modeling of these 2 systems, and we discuss alternative explanations for the excess UV radiation, such as emission of cyclotron harmonics, and heating via irradiation of the white dwarf atmosphere. Support for this research was provided by NASA GALEX grant NNG05GG46G. Recent work has suggested that the accepted evolutionary track for cataclysmic variables, CVs, may be in error. Measurements of carbon abundances have suggested that the secondary stars in these systems may have undergone far more changes during the formation of the CV than previously thought. Also magnetic and non-magnetic CVs appear to follow different evolutionary tracks. A principal probe of this evolution are metal abundance in the secondary star. To expand our understanding in this area we have obtained near infrared spectra of a sample of CVs with SPEX on the NASA Infrared Telescope Facility. These data permit quantitative measurements of carbon and other metal abundances in the secondary stars with the aid of a stellar atmosphere model. We have used the program SPECTRUM to generate these models. We find that both AE Aqr and GK Per show extreme carbon 12 deficits. In the future we plan to extend these models to include Na, Mg, and Fe.