Surya Siddhanta
अन्तराम्शैर् अथावृत्य पश्चाच् छेषैस् तथाधिके । एवम् विषुवती छाया स्वदेशे या दिनार्धजा ॥
At a given place, when the Sun comes to the equinoctial, the shadow (of the Gnomon of 12 digits) cast on the Meridian Line at noon is called the Palabhá or the equinoctial shadow (for that place).
english translation
antarAmzair athAvRtya pazcAc cheSais tathAdhike । evam viSuvatI chAyA svadeze yA dinArdhajA ॥
hk transliteration by Sanscript