We report the discovery of a possible new VY Scl-type cataclysmic variable associated with previously unidentified X-ray source 1RXS J075330.1+044606. The variable optical object USNO-B1.0 0947-0148659 (07:53:30.78 +04:45:56.3, J2000) located 15" from the X-ray source listed in the ROSAT All Sky Survey Faint Source Catalog (Voges et al., 2000, IAUC, 7432) was identified from information listed in the USNO-B1.0 catalog (Monet et al. 2003, AJ, 125, 984): B1=19.82, R1=19.01, B2=17.48, R2=15.69, I=15.52 as suggested by Denisenko & Sokolovsky (2011, AstL, 37, 91).

The lightcurve obtained from NEAT archival images ( http://skyview.gsfc.nasa.gov/skymorph ) shows the object slowly varying between the high (~15m) and low (~20m) states. Since April 2011 we have been monitoring USNO-B1.0 0947-0148659 with the Bradford Robotic Telescope ( http://www.telescope.org ). During April and May 2011 the object was fainter than 18m. After the seasonal gap due to the solar conjunction the object was found to grow systematically at the rate of about 1.1m/100days. Time series photometry with the 40cm telescope of the Ka-Dar observatory (Karachay-Cherkessia, Russia) obtained on February 11, 2012 revealed light variations around R=15.8 with an amplitude of ~0.4m and a possible periodicity of 0.133d. The 1.5m Russian-Turkish telescope (TUBITAK National Observatory, Turkey) spectrum obtained on February 10, 2012 shows Balmer emission lines, but no indication of HeI or HeII.

Based on the historical lightcurve and the absence of features typical for magnetic cataclysmic variables in its spectrum we conclude, that 1RXS J075330.1+044606/USNO-B1.0 0947-0148659 is likely a VY Scl-type system currently rising from its low state.

Further time-resolved observations of this object are encouraged.

DSS finding chart for 1RXS J075330.1+044606, 10'x9', North is up, East is to the left.

The object is listed in 2MASS infrared catalog as 2MASS 07533078+0445557 with the following magnitudes: J=15.017+/-0.037, H=14.848+/-0.060, K=14.706+/-0.093 and in GALEX ultraviolet catalog as GALEX J075330.8+044556 (FUV=15.10+/-0.01, NUV=14.97+/-0.01).

Comparison of DSSI and DSSII plates.

Stacked deep NEAT image showing the object at minimum in 2000-2001.
The image is 5'x5', North is up, East is to the left.

1RXS J075330.1+044606 spectrum obtained by A. Mescheryakov (IKI) with 1.5-meter Russian-Turkish Telescope RTT150 and TFOSC camera on February 10, 2012.

Historical lightcurve of 1RXS J075330.1+044606. The variable was at its historical maximum brightness on the Quick-V photovisual plate taken on 1985 Jan. 18 and is present in GSC 2.3.2 catalog at magnitude V=14.57.

Lightcurve of 1RXS J075330.1+044606 obtained on February 11, 2012 with the 40cm telescope of the Ka-Dar observatory (Karachay-Cherkessia, Russia).

Bradford Robotic Telescope photometry
USNO-A2.0 0900-05516657 (R.A.=07 53 34.40, Dec.=+04 45 18.2, R=15.1, B=15.3) was used as the comparison star. The unfiltered magnitudes with Red zero point are listed in table below:

      JD(UTC)    Mag.                                                 
    2455893.703 17.15
    2455913.664 16.80
    2455921.658 16.73                                   
    2455943.634 16.36                                              
    2455968.538 16.01        

Photometry of DSS plates
USNO-A2.0 0900-05516657 (R=15.1) was used as the comparison star.

      JD(UTC)   Mag.                                                 
    2435456.860 17.6
    2435456.874 18.0
    2446083.836 14.9
    2448222.954 15.6
    2450467.808 15.7
    2450509.677 16.2
    2450517.710 16.8
    2450545.667 16.1
    2450751.966 15.3

Photometry of images from the NEAT archive
USNO-A2.0 0900-05516657 (R=15.1) was used as the comparison star.

      JD(UTC)    Mag. 
    2450810.08634 15.22
    2450810.09644 15.07
    2450810.10662 15.11
    2451870.06189 19.73
    2451870.07241 19.68
    2451870.08295 19.54
    2451882.04311 19.76
    2451882.05367 19.70
    2451882.06475 19.27
    2451963.80698 19.53
    2451963.81698 19.80
    2451971.76993 20.10
    2451972.77801 19.98
    2451972.78797 19.96
    2452256.91479 19.39
    2452256.93192 19.65
    2452256.95182 19.71
    2452262.12949 19.16
    2452262.13972 19.38
    2452262.15021 19.11
    2452267.93513 18.47
    2452267.94567 19.36
    2452267.95637 18.80
    2452283.78770 19.89
    2452283.81964 19.46
    2452283.84948 20.66
    2452313.64985 19.72
    2452313.67045 19.38
    2452313.69319 19.73
    2452325.60612 19.23
    2452325.62648 19.69
    2452325.64927 19.32
    2452617.05990 16.39
    2452617.07076 16.34
    2452617.08160 16.28
    2453010.99378 15.17
    2453011.00517 15.42
    2453021.88973 15.18
    2453021.90091 14.99
    2453021.91193 14.94
    2453034.88372 15.26
    2453034.89454 15.33
    2453034.90502 15.23
    2453070.74699 15.41
    2453070.75737 15.40
    2453074.72228 15.15
    2453074.73301 15.04
    2453074.74380 15.11
    2453080.91220 15.45
    2453080.92271 15.50
    2453080.93310 15.40
    2453097.73789 15.26
    2453097.74825 15.48
    2453097.75859 15.20
    2453098.72900 15.27
    2453098.73936 15.20
    2453098.74970 15.20
    2454092.00331 15.16

Ka-Dar 40cm
The magnitude scale was calibrated using red magnitudes of nearby USNO-B1.0 stars.

      JD(UTC)       Mag.   Err.
    2455969.22703  15.864 0.023
    2455969.22803  15.800 0.020
    2455969.22911  15.768 0.019
    2455969.23037  15.760 0.018
    2455969.23149  15.779 0.021
    2455969.23256  15.759 0.020
    2455969.23390  15.769 0.029
    2455969.23490  15.674 0.020
    2455969.23596  15.650 0.020
    2455969.23735  15.714 0.018
    2455969.23839  15.695 0.022
    2455969.23946  15.760 0.021
    2455969.24069  15.698 0.024
    2455969.24169  15.717 0.024
    2455969.24282  15.715 0.031
    2455969.24396  15.704 0.025
    2455969.24535  15.618 0.026
    2455969.24654  15.620 0.024
    2455969.24767  15.712 0.025
    2455969.24874  15.616 0.021
    2455969.24980  15.675 0.020
    2455969.25097  15.734 0.018
    2455969.25205  15.571 0.021
    2455969.25321  15.559 0.019
    2455969.25421  15.605 0.018
    2455969.25545  15.557 0.015
    2455969.25654  15.506 0.014
    2455969.25772  15.566 0.015
    2455969.25884  15.744 0.016
    2455969.25985  15.679 0.014
    2455969.26089  15.642 0.014
    2455969.26192  15.601 0.014
    2455969.26306  15.670 0.015
    2455969.26405  15.621 0.014
    2455969.26524  15.598 0.013
    2455969.26638  15.594 0.014
    2455969.26744  15.628 0.013
    2455969.26851  15.554 0.014
    2455969.26958  15.549 0.013
    2455969.27068  15.583 0.013
    2455969.27193  15.590 0.016  
    2455969.27307  15.599 0.014  
    2455969.27411  15.644 0.014  
    2455969.27512  15.662 0.014  
    2455969.27635  15.627 0.017  
    2455969.27744  15.642 0.016  
    2455969.27851  15.667 0.015  
    2455969.28031  15.678 0.015  
    2455969.28132  15.694 0.014  
    2455969.28233  15.665 0.013  
    2455969.29483  15.691 0.014  
    2455969.29596  15.606 0.013  
    2455969.29697  15.616 0.014  
    2455969.29802  15.613 0.014  
    2455969.29913  15.642 0.014  
    2455969.30024  15.687 0.015  
    2455969.30154  15.642 0.014  
    2455969.30269  15.609 0.013  
    2455969.30383  15.625 0.015  
    2455969.30508  15.714 0.016  
    2455969.30632  15.675 0.015  
    2455969.30758  15.628 0.017  
    2455969.30873  15.627 0.016  
    2455969.30990  15.664 0.016  
    2455969.31096  15.666 0.018  
    2455969.31213  15.732 0.020  
    2455969.31325  15.635 0.019  
    2455969.31451  15.636 0.022  
    2455969.31566  15.591 0.017  
    2455969.31685  15.640 0.017  
    2455969.31793  15.624 0.017  
    2455969.32648  15.835 0.020  
    2455969.32759  15.774 0.020  
    2455969.32896  15.858 0.023  
    2455969.33001  15.840 0.019  
    2455969.33112  15.687 0.020  
    2455969.33214  15.737 0.018  
    2455969.33324  15.806 0.022  
    2455969.33435  15.859 0.023  
    2455969.33541  15.875 0.022  
    2455969.33660  15.839 0.022
    2455969.33771  15.874 0.023  
    2455969.33885  15.804 0.021  
    2455969.34019  15.866 0.021  
    2455969.34128  15.841 0.022  
    2455969.34259  16.033 0.026  
    2455969.34360  15.993 0.025  
    2455969.34473  15.935 0.024  
    2455969.34587  15.919 0.022  
    2455969.34703  15.860 0.023  
    2455969.34836  15.937 0.024  
    2455969.34941  15.986 0.026  
    2455969.35058  16.001 0.026  
    2455969.35168  16.015 0.029  
    2455969.35291  15.936 0.024  
    2455969.35404  15.985 0.028  
    2455969.35514  15.840 0.024  
    2455969.35624  15.901 0.027  
    2455969.35775  15.870 0.031  
    2455969.35882  15.919 0.027  
    2455969.36006  15.927 0.027  
    2455969.36126  15.979 0.028  
    2455969.36227  15.901 0.026  
    2455969.36329  15.833 0.025  
    2455969.36447  15.902 0.024  
    2455969.36561  15.933 0.027  
    2455969.36663  15.885 0.026  
    2455969.36777  15.818 0.024  
    2455969.36885  15.881 0.025  
    2455969.37007  15.849 0.024  
    2455969.37113  15.854 0.025  
    2455969.37222  15.841 0.029  
    2455969.37331  15.782 0.024  
    2455969.37433  15.912 0.030  
    2455969.37586  15.853 0.029  
    2455969.37706  15.770 0.026  
    2455969.37836  15.590 0.024  
    2455969.38019  15.660 0.028  
    2455969.38267  15.666 0.026  
    2455969.38374  15.719 0.029  
    2455969.38494  15.705 0.024  
    2455969.38606  15.664 0.025
    2455969.38713  15.650 0.023  
    2455969.38825  15.657 0.025  
    2455969.38961  15.685 0.026  
    2455969.39094  15.597 0.022  
    2455969.39201  15.624 0.024  
    2455969.39332  15.677 0.025  
    2455969.39443  15.625 0.024  
    2455969.39559  15.658 0.025  
    2455969.39683  15.624 0.025  
    2455969.39799  15.828 0.032  
    2455969.39907  15.753 0.030  
    2455969.40027  15.745 0.033  
    2455969.40164  15.555 0.023  
    2455969.40321  15.676 0.026  
    2455969.40432  15.699 0.035  
    2455969.40537  15.888 0.042  
    2455969.40681  15.693 0.052  
    2455969.40816  15.653 0.040  
    2455969.40958  15.703 0.032  
    2455969.41089  15.759 0.038  
    2455969.41223  15.754 0.034  
    2455969.41329  15.764 0.039  
    2455969.41450  15.883 0.041  
    2455969.41565  15.954 0.044  
    2455969.41688  15.966 0.036  
    2455969.41821  15.958 0.038  
    2455969.41987  15.996 0.043  
    2455969.42100  15.878 0.045  
    2455969.42225  15.766 0.034  
    2455969.42332  15.801 0.042  
    2455969.42484  15.791 0.048  
    2455969.42587  15.668 0.055  
    2455969.42711  15.714 0.050  
    2455969.42822  15.717 0.057  
    2455969.42928  15.683 0.056  
    2455969.43044  15.813 0.072  
    2455969.43163  15.963 0.111  
    2455969.43278  15.855 0.090  
    2455969.43392  15.658 0.071  
    2455969.43507  15.848 0.080  
    2455969.43623  15.750 0.064
    2455969.43743  15.828 0.066  
    2455969.43851  15.817 0.062  
    2455969.43963  15.771 0.066  
    2455969.44071  15.763 0.073  
    2455969.44170  15.799 0.091  
    2455969.44285  15.858 0.132  
    2455969.44395  15.890 0.149  
    2455969.44510  15.596 0.131  
    2455969.44648  15.767 0.138  
    2455969.44780  15.680 0.212  
    2455969.44889  15.973 0.209  
    2455969.45003  15.518 0.162  
    2455969.45128  15.798 0.099  
    2455969.45424  15.844 0.103  
    2455969.45583  15.612 0.157  
    2455969.46448  15.893 0.160  
    2455969.46618  15.759 0.185  
    2455969.46728  15.885 0.169  
    2455969.46839  15.812 0.142  
    2455969.47000  15.619 0.098  
    2455969.47127  15.830 0.191  
    2455969.47472  15.928 0.212  
    2455969.47574  15.912 0.122  
    2455969.47692  15.989 0.133  
    2455969.47913  15.988 0.161  
    2455969.48023  15.886 0.173  
    2455969.48447  16.089 0.194  
    2455969.48554  16.150 0.213