yoga with grace

कायेन्द्रियसिद्धिरशुद्धिक्षयात् तपसः 

kayendriya siddhirasuddhiksayat tapasah

From discipline, the body and senses become perfect through destruction of impurities.

Yoga Sutras of Patanjali, 2.43

kaya = physical body
indriya = senses
siddhih = perfection
asuddhi = of impurities
ksayat = destruction
tapasah = from discipline

This summer have been spending a lot of time at night on a mound next to castle ruins in Hastings because my son loves looking at the stars and astrophotography.

Wonder what kind of discipline allows the stars to be?