Chandra Release - November 21, 2001

Visual Description: 44i Bootis

 This graphic of 44i Bootis is an artist’s Illustration that showcases a double star system. The illustration depicts the two closely orbiting stars of 44i Bootis. These two stars circle around each other at a rapid rate, passing in front of one another every three hours. By using the Doppler effect – the same process that causes the frequency of an ambulance's siren to shift up and down as the ambulance approaches and recedes – astronomers were able to pinpoint the location of the source of most of the X-rays from this system. They found to their surprise that the large white spot near the top of the larger star produces at least half of the X-rays from this system. In contrast, the X-ray active regions on our Sun tend to be near the equator.