Validation of observations obtained with a liquid mirror telescope by comparison with Sloan Digital Sky Survey observations

The results of a search for peculiar astronomical objects using very low resolution spectra obtained with the NASA Orbital Debris Observatory (NODO) 3 meter diameter liquid mirror telescope (LMT) are compared with results of spectra obtained with the Sloan Digital Sky Survey (SDSS). The main purpose of this comparison is to verify whether observations taken with this novel type of telescope are reliable. This comparison is important because LMTs are a novel type of inexpensive telescope that are very useful for astronomical surveys, particularly surveys in the time domain, and a validation of data taken with an LMT, by comparison with data from a classical telescope, will validate their reliability. We start from a published data analysis that classified only 206 of the 18,000 astronomical objects observed with the NODO liquid mirror telescope as peculiar. A total of 29 of these 206 objects were found in the SDSS. The reliability of the NODO data can be seen by the results of the detailed analysis that, in practice, less than 0.3% of the 18,000 spectra were incorrectly identified as peculiar objects, most probably because they are variable stars. We conclude that the liquid mirror telescope gave reliable observations, comparable to those that would have been obtained with a telescope using a glass mirror.