MC : blue
CC : yellow

Nugget to close the star about 20 m needed
with RS facing and starting where you graft icord (in CC) in clue 1
pick up and k3 stitches in the icord
(pick up and knit 3 (in the icord stitch on WS), M1) x 5, pick up and k3
pick up and k one stitch for center (where all the parallelograms are together)
pick up and knit 23 sts in MC icord (still the stitch closer to WS)… as it’s the cast on icord we don’t need to M1 !!!
turn
pick up and k 3 stitches in MC icord, knit (23+1+23) sts, sl3wyif

right short rows #1
k3 (icord), k to 2 sts before central st, turn
k to last 3 sts, sl3wyif
repeat k3, k to 2 sts before last turn, turn, k to last 3 sts, sl3wyif
and at the same time… on RS when you are at 3, 6, 9 garter ridge high change (k3 for icord) by (k2, ssk)

you should have 9 turns and 10 garter ridges / and 23 stitches on right side of central st (3 icord + 20)

k to 1 st before central st, closing gaps by k2tog the garter bump (one row below on right needle) and the first st on left needle, central double decrease (sl2 as to k2tog, k1, psso), k to last 3 sts, sl3wyif

left short rows #1
k3 (icord), k to 1 st before central st (because 2nd one was decreased in cdd on previous row), turn
k to last 3 sts, sl3wyif
repeat k3, k to 2 sts before last turn, turn, k to last 3 sts, sl3wyif
and at the same time… on WS when you are at 3, 6, 9 garter ridge high change (k3 for icord) by (k2, ssk)

you should have 9 turns and 10 garter ridges / and 22 stitches on left side of central st (3 icord + 19)

k to last 3 sts, closing gaps by k2tog the garter bump (one row below on right needle) and the first st on left needle, sl3wyif
3+19+1+19+3 = 45 sts

Repeat right & left short rows : one (or 2?) less short row on each side, still 3 decreases near icord, the last decrease is made on the row you pick up gaps. (37 sts)

cut yarn leaving about 40 cm of yarn
with RS facing graft icord (such as in end of clue 1)
then turn shawl on WS and 3 needle bind off the 2 halves (right short rows on a needle, left short rows on the other) finishing with a k3tog (because of central st)

notes to make it less curvy : maybe make more decreases near icord, starting on second RS row (the one where you start short rows), and every other RS row