The most accepted root of Hebrew KOCHAV
is on the basis of the Ugaritic KBKB,
regarded by the linguists to be a double replication of KB,
as in KAB.KAB which then went to Syrian KAWKAB
and this to Hebrew KOCHAV,
with KB allegedly meaning "brightly burning",
and this is Latvian KUP "smolder, smoke, burn".
 and nearly the same as Latvian KUOP- or CHUP- "many, heap"
and ZIB- "shine, glimmer, twinkle".

Many Latvian and Afro-Asiatic terms for heavenly "deities"
are much the same. 
Here we need mention only Latvian PERKOns "thunder and lightning", which we find as BARQU and BUR(A)QU "lightning"
in Sivan´s Northwest Semitic Vocables
and as BERQU and BIRQU in Akkadian "lightning"
which is set as equivalent to Sumerian NIM.GIR (gi-ri)
which is Latvian GRA- Lithuanian GRIAU-, GRIA- "to thunder".

The Latvian word for "ray of light" is STAR which gave us our English word STAR and Latvian STARINI "rays of light" gave the German STERNE "stars". English "star" has been traced to proto-Indo-European *ster(3), allegedly the root of  "star" - which is totally incorrect - since proto-Indo-European *ster(2) means "spread out, ray". The schwa is older so that star- is older than *ster.

There are another group of Indo-European words meaning star,
e.g. Latvian ZVAIG-ZNE Lithuanian ZVAIGZDE, Russian zvezda,
Polish gwiazda - which the linguists have traced to some impossible root, whereas Latvian SVEK-IS "wax, tallow, burning candle"
gives us the correct root.