http://www.skyandtelescope.com.au 51
by Sue French TARGETS
ROGELIO BERNAL ANDREO
The star-clad maiden
VisitVirgotofindtheseexemplarygalaxiesofautumn.
WouldyouthestarofBacchusfind,
on noble Virgo’s wing,
AlengthyrayfromHydra’sheart
unto Arcturus bring;
Two-thirdsalongthatfanciedline,
direct th’ inquiring eye,
Andtherethejewelwillbeseen,
southofCorCaroli.
— William Henry Smyth,
The Bedford Catalogue, 1844
T
his charming quatrain describes
how to find the star Vindemiatrix
in Virgo using the Alpha stars of
Hydra, Boötes and Canes Venatici as
guides. The tie between Virgo and the
Roman god Bacchus (Greek Dionysus)
has many versions, but a woeful tale
is told by Julius D. W. Staal in his
wonderful book The New Patterns in the
Sky. Bacchus taught Icarius, a mortal
man, the art of winemaking. Icarius
shared his newly created libation
with friends and local shepherds,
who mistook their intoxication for
attempted poisoning and slew poor
Icarius. His body, tossed aside in a
ditch, was found by his faithful dogs
and his daughter Erigone. In their
grief, they followed him into death.
Icarius was then placed in our sky as
Boötes, his dogs as Canes Venatici, and
Erigone as Virgo.
The area of the sky we’ll be visiting
lies west of Vindemiatrix and within the
Virgo Cluster, which hosts about 1,500
galaxies. The cluster’s main body is
centred on the hefty galaxy Messier 87,
sitting 54 million light-years away from
us. Including dark matter, M87 weighs
in at roughly 10 trillion solar masses or
around 10 Milky Way galaxies.
Through my 130-mm refractor
at 23×, M87 is an obvious glow just
south of a deep-yellow, 8.6-magnitude
star. It appears slightly oval at 63×
and brightens considerably toward
the centre. Examined at 117×, M87’s
brightness contours become rounder
as you approach the centre, and they
enfold a small, brilliant core. The halo
has indefinite boundaries, but I’d put
the size at about 4½′. Nearby NGC 4478
also is visible, looking fainter and more
obviously oval than M87. Its plump
profile tilts northwest and is roughly
S This deep image of the Virgo cluster
represents more than 36 hours of exposure.
One easy route to the galaxy cluster hops from
Epsilon (ε) Virginis (Vindemiatrix) to Rho and 27
Virginis. From those stars, it takes just a nudge
to bring the galaxies into the ield of view.
M60
M59
M58
NGC 4568
NGC 4564
M87
NGC 4478 NGC 4476
M89
M90
N
27 Vir
ρ
NGC 4567
NGC 4550
NGC 4551