Parse this person name:

Jesse Geertsen (1804-1869, flourished 1819-1848)
user
first_name: Jesse
last_name: Geertsen
middle_names: []
temporal:
- start: 1804
  end: 1869
  type: life_span
- start: 1819
  end: 1848
  type: flourished
titles: []
extra_info: []
assistant