Arp199
Galaxy in Boötes
About
NGC 5544 and NGC 5545, an interacting pair of spirals in Boötes, with distances of about 140 and 158 million light-years given for the two. Arp listed them among galaxies with material ejected from nuclei. NGC 5544 is the brighter barred galaxy at magnitude 14.0; NGC 5545 is far fainter at 18.5 and spans only about 0.08′.
Imaging tips
- Only about 2′ across, so the pair is too small to frame: use a long focal length and a fine pixel scale.
- Faint at 23.1 mag/arcsec², so plan many hours of broadband data; NGC 5545 at magnitude 18.5 will need the deepest stack.
- One imager's LRGB frame used 2 h 40 min of luminance, then 30, 40 and 40 min of red, green and blue, about 4.5 hours in all, and its 39′ field also took in NGC 5557.
- Best around April and May, when it reaches about 77° from 50°N.
Facts
- Size
- 2′ × 2′
- Magnitude
- 13.0
- Coordinates
- RA 14h 17.0m, Dec +36° 34′
- Framing, APS-C
- longer than 4000 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Apr, May
- Peak altitude
- 77° from 50°N, 88° from 35°N