There is only the observable Universe.
The Universe is expanding at exactly the velocity of light.
This explains cosmic isotropic as 'c' has always been the same.
The Universe is closed, positively curved and asymptotically flat.
Note that HD 140283 is estimated to be 14.46±0.8 billion years old.
Derivation of the Hubble-Slipher Constant for a Universe age
of
14.57 billion years given a
velocity-of-light expansion rate.
Kilometers in a megaparsec: 3.08567758
× 1019
One year = 31,556,926 seconds
Universe at age UAge is t = 14.57 billion years.
Assumed.
Universe UAge is t = 31,556,926 × 14.57 × 109 = 4.5978441 × 1017 seconds
Diameter ct = 299792.458 km/sec × 4.5978441 × 1017 sec = 1.37839899; 1023 km
Diameter is ct = 1.37839899 × 1023 / 3.08567758 × 1019 mega parsecs
Universe Diameter is ct = 4467.0869 mega parsecs
Hubble-Slipher Constant is H = c per UD = velocity of light per Universe Diameter
H0 = 299792.458 km/sec per 4467.0869 mega parsec
H0 = 67.111 km/s per Mega Parsec
For different assumed Universe Ages here are corresponding Hubble values.