Danish: Hansen / Hænsen [Pronunciation ]

[dihydrogen monoxide]

If I write the surname Hansen in Danish, would /a/ be pronounced the same if I write the surname Hansen as Hænsen. If not what is the difference in quality between /a/ and /æ/ in Standard Danish.

 

[PoulBA]

If you consider the unrounded frontvowel inventory in Danish to be divided in four: i - e - æ - a, you'll see that it is a question of openness. /a/ is one degree more open than /æ/. Disregarding length, think of the English vowels in Ben and ban or ten and tan.
There is, however, a tendency in modern Danish - younger speakers / Copenhagen dialect - that /a/ in words like Hansen is narrowing towards /æ/.