RCW 88 of a larger halo of fainter nebulosity extending perhaps out to 10 arcmin. The RCW catalogue states the Hα image size is 3'×2. RCW 88 is located about 3300 parsecs (10,000 light years) from us, though other estimates place this at a closer 1800±300 pc. or 1800±200 pc. Assuming the former distance and the diameter as 5'-6' across, finds by simple trigonometry the true size subtends a minimum of 5±1 parsecs (16±3 light-years.) This small emission nebula shows a mean radial velocity of −18 km.s, and is also a faint radio source that was identified by Lloyd Higgs in 1971.
Kos (unit) Kos (unit) The kos (Sanskrit: कोस), also spelled Kosh, Krosh, krosha and Koss, is an ancient Indian subcontinental "Arthashastra standard unit" of distance, since at least 4 BCE. A kos is about 3.00 km or 1.91 miles. The ""Arthashastra: Chapter XX. Measurement of space and time"", authored in 4th century BCE by Chanakya (Vishnugupta Kauṭilya), sets this standard breakup of Indian units of length: Kos may also refer to roughly 1.8 km (1 mile) or 3.2 km (2 miles). "Arthashastra Standard unit" of Kos or krosh is equal to 3075 metres in SI units and 1.91 miles in Imperial units.