[shell] How do you grep a file and get the next 5 lines

How do I grep a file for 19:55 and get the Line 1,2,3,4,5?

2013/10/08 19:55:27.471
Line 1
Line 2
Line 3
Line 4
Line 5

2013/10/08 19:55:29.566
Line 1
Line 2
Line 3
Line 4
Line 5

Some awk version.

awk '/19:55/{c=5} c-->0'
awk '/19:55/{c=5} c && c--'

When pattern found, set c=5
If c is true, print and decrease number of c

Here is a sed solution:

sed '/19:55/{
N
N
N
N
N
s/\n/ /g
}' file.txt