SKY_September2014.pdf

60 September 2014 sky & telescope

Steve Gottlieb

Going Deep

Seeking Interacting Galaxies

The Vorontsov-Velyaminov catalog is a mother lode of close galaxy pairs.

Sky Survey,

conducted from 1949 to 1956 using the 48-inch Oschin

Schmidt Telescope, recorded stars as faint as 21st magni-

tude, along with countless deep-sky objects. The 936 pairs

of blue- and red-sensitive plates provided one of the most

important resources for astronomical research for the

next several decades.

One of the fi rst studies based on the new sky survey

was the 1959 Atlas and Catalogue of Interacting Galax-

ies by Russian astronomer Boris Vorontsov-Velyaminov.

It lists 355 systems with designations VV 1 through VV

355. Although some were previously known, Vorontsov-
     Velyaminov discovered most of them by visual inspection
     of the Palomar Observatory Sky Survey plates.
     The fi rst VV atlas divides interacting galaxies into 20
     classes such as “merging or in contact,” “nests of galax-

The palomar observatory ies,” and “chains with bridges.” It also notes various

interactions, such as tidal tails, distortions, and rings.

The atlas showcases a number of bizarre, gravitation-

ally deformed galaxies, and it caught the attention of the

ANDROMEDA

ARIES

CYGNUS

DELPHINUS

EQUULEUS

LACERTA

PEGASUS

PISCES

TRIANGULUM

M15

M31 M29

M32

M33

M34

M39

M74

M110

891

7006

VV 254

VV 323

VV 102

α

α α

α

α

α

α

α

β

β

β

β

β

β

δ

δ

δ

δ

ε

ε

ε

ε

ε

φ

φ

γ

γ

γ

γ

γ

γ

γ

η

η

η

η

ι

ι

κ

κ

λ

λ

μ

μ

ν

ν

ν

o1

ο

ο

ο π^2

π

π

θ

ρ

σ

τ

τ

τ

υ

υ

υ

υ

ω

ξ

ξ

ζ

ζ

ζ ψ

58

59

83

16

17

2 h

+30°

0 h 22 h 21 h 20 h

+20°

+10°

+40°

1 h 23 h

Star magnitudes

2

3

4

5

6

Selected Vorontsov-Velyaminov Galaxy Pairs

Name UGC Mag(s) Const. RA Dec.

VV 254 12914, 12915 12.5, 13.0 Peg 0h 01.6m +23° 29 ′

VV 323 (Arp 273) 1810, 1813 12.6, 14.2 And 2h 21.5m +39° 23 ′

VV 102 11672 ~14.5 Del 21h 04.5m +16° 05 ′

Visual magnitudes have been estimated by correcting the blue magnitudes in

the Third Reference Catalog of Bright Galaxies for galaxy type. Only a combined

magnitude is available for VV 102; the components are too tightly bound to measure

separately. Right ascension and declination are for equinox 2000.0.

GD layout.indd 60 6/23/14 12:20 PM