Archadle King [From 'Sancta Missa']: The Pope retires to the throne to make his Communion. The following ceremonies are observed: The cardinal deacon first takes the paten, on which the master of ceremonies has placed the asterisk, elevates it to the height of his forehead so that it may be seen by the people, turns to the right to show it to the Pope, raises it higher in making a semicircle, and then returns to the left in such a way that it may be exhibited for the third time to both the faithful and the Pope.
The subdeacon, kneeling at the gospel side of the altar, receives the paten and asterisk, and takes them to the Pope, his hands covered by a rich veil embroidered with gold (linteum pectoralis). The asterisk is a safeguard in the form of a star, which is placed over the paten as a covering for the Host when it is carried to the throne. It has twelve rays on which are inscribed the names of the twelve Apostles. In the Byzantine rite, an asterisk is a normal liturgical ornament, which is employed to prevent the veil from touching the Eucharistic bread. The Eastern type is formed by two half circles, with a little star suspended in the centre.
The chalice is elevated by the cardinal deacon with the same ceremony as for the paten. Then the master of ceremonies covers the chalice with a gold-embroidered pall, and the deacon takes it to the throne. Two archbishops hold the book for the communion prayers; while a third assists with a hand-candle. The second master of ceremonies removes the asterisk, and the Pope, taking two particles of the Host in his left hand, says: Panem coelestem and Domine non sum dignus. Innocent III (1198-1216) makes no mention of the formulas, but they are found in the Ordo of Cardinal d'Estouville (1402-82) at the end of the 15th century. A second commixture was formerly customary after the Communion of the Pope, and Ordo Romanus I says: Qui dum communicaverit, de ipsa Sancta quam momorderit ponit in calice in manus archidiaconi dicendo: Fiat commixtio ....(6) Ordo Romanus VII supplies the rubric: Et expleta confractione, quando communicat domnus apostolicus partem sibi mordet et reliquam in calicem mittit faciens crucem de ea tribus vicibus super calicem, nihil dicens.(7) The deacon approaches with the chalice, and the sacristan gives the fistula to the assistant bishop. Then the Pope places the futula in the chalice, and so receives the precious Blood.(8) The Agnus Dei is concluded by the choir after the Pope has made his Communion.
From Wikipedia: In the Roman Rite, a special twelve-ray asterisk was used in Papal Masses, as a covering for the host on the paten, when it was brought to the Pope at his throne for his Communion. Unlike the Eastern asterisk, which has four rays, the Papal asterisk had twelve rays, each inscribed with the name of an Apostle. Its use has been recently revived by Pope Benedict XVI.
From Wikipedia: An asterisk - a common eucharistic implement in the Eastern Rites, in which it is shaped differently from the twelve-ray asterisk that was used in Papal Masses - was used to cover the host on the paten, when it was brought to the Pope at his throne for communion.
From Wikipedia: The master of ceremonies placed a twelve-rayed asterisk on the paten, to cover the Host.