What to Do with Hwæt

The first word of Beowulf is hwæta common enough word in Old English, and the source of our word what, but a difficult one to translate here. It doesnt seem to be a part of the sentence, it just hovers there in front of it. Different translators have had to find their own way of rendering hwæt:

John M. Kemble (1837): Lo!
Benjamin Thorpe (1855): Ay
Thomas Arnold (1876): What!
J. Lesslie Hall (1892): Lo!
John R. Clark Hall (1901): Lo!
Ernest J. B. Kirtlan (1914): Now
William Ellery Leonard (1923):...