LHO Logo Lizard Hollow Observatory:  Research

 

Current Observational Programs

    Photometry of Visual Double Stars

        Modern magnitudes and colors are lacking for the components of thousands of visual double stars.   LHO's primary long-term program will be to obtain standard  UBVRCIC  CCD photometry for those systems that are within reach of the 28-cm Beardsley telescope.



    Symbiotic Binary Stars

        Time-resolved and long-term UBVRCIC  photometry of symbiotic binary stars will be LHO's second area of research.    These binary stars are composed of a cool giant star and a hot star enveloped by a gaseous nebula.    Their spectra and their photometric and spectroscopic behaviors are extremely complex and interesting,   providing,  in some cases,  the opportunity to observe a planetary nebula evolve.    With CCD cameras,  it is possible to observe their photometric behavior over an unprecedented range of wavelengths and with an order of magnitude improvement in photometric precision and accuracy over visual or photographic magnitudes.

 

   Mass Determinations of Eclipsing Double-Line Spectroscopic Binary Stars


         One of only two direct methods for determining the masses of stars is from observing binary stars which are eclipsing binaries (EBs) and also double-line spectroscopic binaries (DLSBs).     Lizard Hollow will observe do photometry for those systems already known to be EBs and DLSBs.    We will do photometry of systems also known to be DLSBs but with poorly known light elements,   or not known to be EBs but whose spectroscopic orbital  elements make it likely that they are in fact EBs.

 

    Early-type variable and potentially binary stars


           LHO will take time-resolved and long-term UBVRCIC  photometric observations of five other types of early-type  (spectral types O-A)  variable and potentially binary stars, all of which are relatively poorly studied:



                    1.   Early-type Irregular Variables:

These are variables the nature of whose light variation features are unknown.    Their spectral types range from O-A,  although the GCVS merely gives some types as "peculiar".    GCVS variable type stars IA and ISA are included in this observing program.     Amplitudes range from about  0.15 mag. to around 2.0 magnitudes.


                    2.   BE Variables:

These are stars of spectral type Be and are related, both photometrically and spectroscopically to the g Cas eruptive variables.    However,  their photometric variations are often of small-amplitude and are unrelated to shell events.    Most interesting,  though,  is that the variations in some stars have appeared to be quasi-periodic.    Amplitudes are generally about 0.15 mag. in the visual and increase with decreasing wavelength.
                              

                    3.   Long-period Blue Variables:

These are pulsating B-stars with periods longer than one day.   GCVS variable type stars LBV are included in this observing program.    The amplitudes of these variables are generally  less than  0.05 mag.,  although several with amplitudes in the neighborhood of   0.1 mag.  are known.


                    4.   PV Telescopii Variables:

Sometimes also called "strong-Helium stars",  these stars are supergiant pulsating stars of spectral type Bp with weak hydrogen lines and strong lines of He and C.    Their amplitudes are about 0.1 V mag.    Apparent periods as short as approximately 0.1 day and as long as about a year are known.


                    5.   "Unique" Variable Stars:

These are stars described by the GCVS as stars which may be in "...short stages of transition from one type of variability to another" or may be at the "...earliest or latest evolutionary stages of these types".    Also included by the GCVS in this type are "...insufficiently studied members of future new types of variables."    Presumably,  there are binary stars lurking amongst the stars in this GCVS classification.    At the least,  we may settle the question of some of these stars' classifications and properties and also discover some interesting new objects along the way.



                   

    Future Research Possibilities

    Below are some long-term research projects in which LHO is interested in pursuing in the future:


I.     Surveys/Other Experiments

    1.   Long-Focal Length Planetary "movies" of:

    2.   Search for Stellar Eclipses by Extra-Solar Planets

    3.   Speckle Interferometry Experiments

 

II.    Future Plans

 

Not Exactly Research, But...


        In early September, 2000,   the rainy season ended and the night skies cleared for the first time since mid-June.    The first successful CCD camera image  - of the Moon   -  was obtained September 12,  2000.    Click here to see it and read something about it.

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This page was updated on February 08, 2006 11:47 PM. E-mail Thom GandetE-Mail Thom Gandet

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