Subject: is it possible for a star massed body to have planet like composition?

would it be physicaly possible, for a celestial body with a mass of 5.0*10^29
kilograms to form in space without it being a star, or having formed like one,
but instead be more planet like in its formation, and composition?would it be
possible for this body to have a radius of 4.14*10^8 meters, a volume of
2.9*10^26 meters^3 and a density of approximately 1700 kg/m^3? if this is
possible, what would be it's most likely composition? and could it form without
developing an atmosphere, or have the atmosphere be removed due to some event
while have the described information at it's completeion?my reason for asking is
much too long to include here, and would take a ,lot of questions, so i will
leave it as it is.

Re: is it possible for a star massed body to have planet like composition?