Arp84
Galaxy in Canes Venatici
About
NGC 5394 and NGC 5395, two interacting spirals in Canes Venatici roughly 165 million light-years away. Arp noted that the larger one has a bright companion sitting where one of its arms ends. At the eyepiece the pair looks like a crescent with brighter ends.
Imaging tips
- Sources give about 1.9′ × 1.0′ and 2.6′ × 1.4′ for the two galaxies, so the pair is too small to frame: use a long focal length and a fine pixel scale.
- One imager collected 7.6 hours in LRGB: 56 × 300 s luminance plus about 12 × 300 s per colour, at 0.265″ per pixel.
- Surface brightness is 22.3 mag/arcsec², so plan many hours of broadband data; narrowband adds nothing for a galaxy pair.
- Best around April and May, when it reaches about 77° altitude from 50°N.
Facts
- Size
- 3′ × 2′
- Magnitude
- 11.7
- Coordinates
- RA 13h 58.6m, Dec +37° 27′
- Framing, APS-C
- longer than 4000 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Apr, May
- Peak altitude
- 78° from 50°N, 88° from 35°N