Australian Sky & Telescope - 04.2019

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

by Con Stoitsis METEORS

meteors per hour to the general rate. The

traditional peak on the morning of May

6 could yield a ZHR of around 50 to 85

meteors from a dark sky; from town you

might get 15 to 20.

This year will present a great

opportunity to catch this shower, what

with the predicted increased activity

and the Moon setting early in the

evening. Happy viewing!

■ CON STOITSIS is director of the

Astronomical Society of Victoria’s comet

and meteor sections. Follow him on

Twitter@vivstoitsis

The old faithful Etas

Twin peaks for this southern shower.

SSaturn hides behind the Moon.

T

he Eta Aquariid meteor shower

is one of the best visible in our

southern skies, active from about

April 19 to May 28. Its meteors are

often fast and bright, with many leaving

trains that last for minutes. The average

magnitude is 2.7, but fireball activity

is usually minimal. Eta’s meteors are

usually yellow, but orange and blue is

also often seen. While the radiant is

still low, this shower’s meteors tend

to have very long paths, so start your

observations early, say around 3:00am.

Recent International Meteor

Organisation (IMO,imo.net)analyses

have shown the zenithal

hourly rate (ZHR) is

generally above 40 in the

periodMay3to10.Thepeak

ratesappeartobevariable—

a relatively broad maximum,

sometimeswithavariable

number of sub-maxima,

occurs around May 5/6.

Modelling of the stream by

Mikhail Maslov suggests two

trail encounters for 2019

—May4,between4hand

10hUTandMay6,between

12hand20hUT—bothof

whichmightadd5to10

if the occultation gets underway
prior to moonrise, you’ll only see
the reappearance. And that’s what
we’re going to get this time. If you’re
anywhere east of a line drawn roughly
from Rockhampton to Adelaide, you’ll
see the Moon rise with Saturn nowhere
in sight. But then, shortly before
midnight, the planet will appear to
wink back into existence as it reappears
on the dark limb of the Moon. Here
are the times of reappearance (in local
time) for major centres:
Rockhampton — 11:15pm
Brisbane — 11:20pm
Sydney — 11:26pm
Canberra — 11:26pm
Melbourne — 11:26pm
Adelaide — 10:54pm
Hobart—11:28pm
Actually if you’re in Tasmania you’ll
gettoseethedisappearancetoo,but
withtheMoonandSaturnverylowon
thehorizon.Thedisappearancetimefor
Hobart is 10:49pm.
IfyoumissthisSaturnoccultation
event,don’tworry—there’llbethree
morelaterintheyear,inAugust,
September and November (the latter
only for New Zealand).

Enif

AQUARIUS Fomalhaut

CAPRICORNUS

PISCIS AUSTRINUS

Looking East

PEGASUS

Eta Aquariids

May 6, 3:00am

APRIL

2 Venus 3° north of Moon

3 Mercury0°.4northofNeptune

3 Mercury4°northofMoon

3 Neptune3°northofMoon

6 Uranus5°northofMoon

9 Mars5°northofMoon

10 Pallas at opposition

11 Jupiter stationary

12 Mercurygreatestelong.west(28°)

17 Mars7°northofAldebaran

24 Jupiter 1.6° south of Moon

25 Saturn occulted by the Moon

30 Saturn stationary

SKY PHENOMENA LUNAR PHENOMENA

APRIL

New Moon ...... 5th, 08:50 UT

First Quarter ...... 12th, 19:06 UT

Full Moon ...... 19th, 11:12 UT

Last Quarter ...... 26th, 22:18 UT

Apogee ...... 1st, 00h UT, 405,577 km

Perigee ...... 16th, 22h UT, 364,205 km

Apogee ...... 28th, 18h UT, 404,582 km