Unanswered Questions

I have a plot in Log(g) vs T_eff coordinates from my stellar evolution model. The parameters of the model are M=0.8 M_solar, [Fe/H]=-1.19, Y=0.245. I want to convert it to the y vs (v-y) coordinates (...

A colour-colour diagram (CCD) like this compares the difference in magnitudes at different wavelengths. The trend in the pattern of colour-colour comparisons tells us about what type of source the ...

From my understanding D4000 is a ratio between the 'flux densities between 4050 and 4250 Angstroms and that between 3750 and 3950 Angstrom', from Poggianti et al (1997). However I do not understand ...

What is the canonical method to calculate the surface brightness limit of a 2D image, e.g., in a 1 arcsec2 aperture? ...if image has erg/s/cm2 units and each pixel has some arcsec2 dimension.

How were interstellar reddening values for cepheid first calculated? I mean, other than using the derived equation to get extinction-corrected magnitude of Cepheids, I want to know how to drive them ...

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In plotting out the magnitude errors in SDSS photometry, I get the following pattern: Why do the errors go up to about 0.5, then down? In other words, why does it look like a high-heeled shoe (or ...

I have several model SEDs generated by the CLOUDY spectral synthesis code. The data is formatted with one wavelength column and one flux column. I wish to perform Hubble synthetic photometry on these ...

I am unable to find this information online, does anyone know of a database, book, or website that contains all of the B-band, V-band, I-band etc.... apparent magnitudes for each star? Thanks for any ...

I am searching all available spectroscopic data (and particularly wavelength interval) of 28 CMa in the constellation Canis Majoris to measure radial velocities. Which database should I use?