A (6)

http://www.skyandtelescope.com.au 47

The Southern

Delta Aquariids

will be best seen

in the hours

before dawn in

late July.

from the Alpha Capricornid

shower, a little below and to

thewest.Althoughthis shower

hasaZHRofaround 5, with

maximum activity usually

around July 30, it will be

Moon-affected this year.

CON STOITSIS

isthedirectoroftheAstronomicalSocietyof

Victoria’s comet and meteor sections.

N

E W

S

ANTONÍNRÜ

KL

Phases

New Moon July 4, 11:01 UT

First Quarter July 12, 00:52 UT

Full Moon July 19, 22:57 UT

Last Quarter July 26, 23:00 UT

Distances

Perigee July 1, 07h UT

365,983 km

Apogee July 13, 05h UT

404,269 km

Perigee July 27, 12h UT

DatesareforAustralianEasternStandardTime 369,662 km

EVENTS OF NOTE

July 2 Mercury at perihelion

2 Aldebaran 0.4° south of the Moon

5 Earth at aphelion (furthest from Sun)

7 Mercury in superior conjunction

8 Pluto at opposition

8 Regulus 1.8° north of the Moon

9 Jupiter0.9°northoftheMoon

11 Venusatperihelion

12 Mercury greatest latitude north

12 Spica 6° south of the Moon

15 Mars 8° south of the Moon

16 Antares 10° south of the Moon

16 Saturn 3° south of the Moon

29 Aldebaran 0.3° south of the Moon

31 Mercury 0.3° north of Regulus

L

ate July will bring one of

the better meteor showers

for Southern Hemisphere

observers, the Southern Delta

Aquariids, so called because the

radiant — the point from which the

meteors appear to fan out across

the sky — is located near the star

delta Aquarii, in the constellation

Aquarius.

The meteoroids that produce

the shower probably had their

origins in the aftermath of the

breakup of a comet that produced

the Marsden and Kracht families

of ‘sunskirting’ comets. The

shower is rich in faint meteors,

but occasionally bright members

have been spotted. Southern Delta

Aquariids are usually blue or

white in colour, with the average

magnitude being +4.0.

The zenithal hourly rate (ZHR)

can vary from 15 to 30 meteors per

hour from a dark rural sky; from

town, rates are usually closer to

8 per hour. (ZHR refers to the

number of meteors you

mightexpecttosee

if they were directly

overhead, ie. looking

through the least

amount of atmosphere).

In previous years

rateshavebeengood

(ZHR5to8),steadily

throughout late July and

early- to mid-August.

For 2016, the

International Meteor

Organisation is predicting that peak

activity may come from July 26 to 31,

when the rather faint meteors will

have to contend with the waning

crescent Moon. By early August

when the Moon is new, conditions

will be ideal to view some of them

just after the predicted peak. Start

observing an hour or two before

dawn, as this usually provides the

best viewing conditions.

While you’re Southern Delta

Aquariid spotting, also keep an

eye out for a few bright meteors

Meteorsspillfromthe

‘water bearer’

The Southern DeltaAquariidsisoneofthe

better showers for southern stargazers.

THE MOON – JULY 2016

CON STOITSIS