Mahābhārata & Rāmāyaṇa · c. 1st–4th c. CE
śyāmo grahaḥ prajvalitaḥ sadhūmaḥ sahapāvakaḥ / aindraṃ tejasvi nakṣatraṃ jyeṣṭhām ākramya tiṣṭhati //
CE lines 06,003.015a/015c.
The white planet (Ketu), blazing up like fire mixed with smoke, stayeth, having attacked the bright constellation Jeshtha that is sacred to Indra. — Kisari Mohan Ganguli (1883-96)
The identification is made inside the verse itself, which is why this is 'certain' rather than inferred: 'the brilliant AINDRA asterism, Jyeṣṭhā' (aindraṃ tejasvi nakṣatraṃ jyeṣṭhām ākramya tiṣṭhati) — Aindra and Jyeṣṭhā are in apposition. Indra is Jyeṣṭhā's presiding deity in every nakṣatra-devatā list, and Jyeṣṭhā's yogatārā is Antares (α Sco) per the Sūrya Siddhānta entry already in the database. The database records 'rohini-indra' (a second Rohiṇī = Jyeṣṭhā, Vedic) and 'indra-mahendra' (a Śiśumāra position) but not Aindra as a nakṣatra name. Ganguli glosses it 'the bright constellation Jeshtha that is sacred to Indra'.
Mahābhārata 6.3.15 (Critical Edition, Bhīṣma Parva) = vulgate/Ganguli Bhīṣma Parva Section III · text · translation