Sky and Telescope - May 2016 - 51

For how to make a scientiﬁc meteor count, see imo.net/visual/major.

Phenomena of Jupiter's Moons, May 2016

May Meteors
Only one major meteor stream, the one
shed by Halley's Comet, intersects Earth's
orbit in two places with both of the resulting showers being visible at night. In October we call them the Orionids, and in May
they're the Eta Aquariids.
Both showers run for several days and
have a reputation for meteors that are
swift and relatively faint. But in May we
apparently pass nearer to the center of the
stream; the Eta Aquariid shower is roughly
three times as strong as the Orionid
shower, and it lasts longer too.
This year the Eta Aquariids should peak
on the mornings of May 5th and 6th, when
they will be untroubled by moonlight. This
is usually the best shower of the year for
the Southern Hemisphere, with perhaps
60 meteors visible per hour before dawn to
an observer under ideal conditions. Meteor
watchers in northern latitudes see fewer,
and those north of 40°° or 45° see hardly
any, because the shower's radiant (at the
Water Jar, the head of Aquarius) is still low
in the east-southeast as dawn brightens.
On the other hand, when a shower's
radiant is low, the few meteors that do
appear will be long, dramatic Earthgrazers,
sometimes ﬂying far across the sky (S&T:
Aug. 2014, p. 64). ✦

May 1

May 2

May 3

May 4
May 5

May 6

Lunar Occultation
If you're out observing the
Moon with a telescope late on the
night of May 17-18, you may notice
that its dark limb is creeping toward
a 4.4-magnitude star: Theta Virginis.
The Moon will go on to occult the
star for viewers all across North
America, although for easterners
the Moon and star will be getting
low in the west.
Some disappearance times: at
Washington, DC, 3:23 a.m. EDT;
Chicago, 2:10 a.m. CDT; Denver,
12:51 a.m. MDT; Los Angeles, 11:36
p.m. PDT. Detailed local timetables
for both the disappearance and
reappearance of the star are at
is.gd/ThetaVirMay2016.

May 7

May 8

May 9

2:18

I.Ec.R

1:21

I.Sh.E

12:51

III.Oc.D

20:09

I.Tr.I

1:26

II.Oc.D

16:13

III.Oc.R

May 24

1:01

III.Ec.R

2:32

I.Ec.R

21:13

I.Sh.I

6:28

II.Ec.R

17:50

III.Ec.D

20:12

I.Tr.I

22:24

I.Tr.E

9:06

III.Oc.D

21:03

III.Ec.R

21:26

I.Sh.I

23:01

II.Oc.D

12:27

III.Oc.R

21:08

I.Oc.D

22:26

I.Tr.E

23:27

I.Sh.E

13:51

III.Ec.D

0:37

I.Ec.R

23:39

I.Sh.E

May 17

3:53

II.Ec.R

17:04

III.Ec.R

18:19

I.Tr.I

5:24

III.Oc.D

19:16

I.Oc.D

19:31

I.Sh.I

22:42

I.Ec.R

20:34

I.Tr.E

4:12

II.Tr.E

16:27

I.Tr.I

21:45

I.Sh.E

6:40

II.Sh.E

22:51

II.Tr.I

17:29

I.Oc.D

1:20

II.Sh.I

21:01

I.Ec.R

II.Tr.E

May 25

1:24

II.Tr.I

3:57

II.Sh.I

8:45

III.Oc.R

9:50

III.Ec.D

13:05

III.Ec.R

17:36

I.Sh.I

17:25

I.Oc.D

18:42

I.Tr.E

20:46

I.Ec.R

19:50

I.Sh.E

1:39

14:37

I.Tr.I

20:20

II.Tr.I

4:04

II.Sh.E

22:43

II.Sh.I

15:36

I.Oc.D

16:55

I.Tr.E

19:05

I.Ec.R

18:08

I.Sh.E

19:40

II.Oc.D

0:55

II.Ec.R

15:41

I.Sh.I

16:51

I.Tr.E

17:52

II.Tr.I

17:56

I.Sh.E

20:06

II.Sh.I

20:39

II.Tr.E

22:51

II.Sh.E

11:52

I.Oc.D

15:15

I.Ec.R

9:04

I.Tr.I

10:10

I.Sh.I

11:19

I.Tr.E

12:13

II.Oc.D

12:24

I.Sh.E

17:11

II.Ec.R

19:09

III.Tr.I

22:27

III.Tr.E

23:41

III.Sh.I

2:53

III.Sh.E

6:20

I.Oc.D

9:44

I.Ec.R

16:29

IV.Tr.I

May 10

May 11

23:08

II.Tr.E

1:27

II.Sh.E

13:44
May 12

May 13

May 14

May 19

I.Oc.D

17:10

I.Ec.R

10:55

I.Tr.I

12:05

I.Sh.I

13:10

May 18

I.Tr.E

14:19

I.Sh.E

14:40

II.Oc.D

19:45

II.Ec.R

22:52

III.Tr.I

2:10

III.Tr.E

3:40

III.Sh.I

6:51

III.Sh.E

8:11

I.Oc.D

11:39

I.Ec.R

5:23

I.Tr.I

6:33

I.Sh.I

7:38

I.Tr.E

8:47

I.Sh.E

May 20

May 21

May 26

14:40

I.Tr.I

15:54

I.Sh.I

12:47

I.Tr.I

13:59

I.Sh.I

15:02

I.Tr.E

6:32

III.Tr.I

16:13

I.Sh.E

9:51

III.Tr.E
III.Sh.I

May 27

17:09

II.Oc.D

11:39

22:20

II.Ec.R

11:57

I.Oc.D

2:40

III.Tr.I

14:48

III.Sh.E

15:29

I.Ec.R

5:59

III.Tr.E

7:40

III.Sh.I

10:04

I.Oc.D

10:50

III.Sh.E

11:23

I.Tr.E

13:34

I.Ec.R

12:37

I.Sh.E

7:15

I.Tr.I

14:41

II.Tr.I

8:28

I.Sh.I

17:15

II.Sh.I

May 28

9:08

I.Tr.I

10:23

I.Sh.I

9:30

I.Tr.E

17:28

II.Tr.E

10:42

I.Sh.E

19:58

II.Sh.E

6:26

I.Oc.D

9:58

I.Ec.R

12:07

II.Tr.I

14:38

II.Sh.I

14:54

II.Tr.E

17:22

May 29
May 30

3:37

I.Tr.I

II.Sh.E

4:52

I.Sh.I

4:32

I.Oc.D

5:52

I.Tr.E

8:03

I.Ec.R

7:05

I.Sh.E
II.Oc.D

19:31

IV.Tr.E

9:35

II.Tr.I

3:18

IV.Sh.I

12:01

II.Sh.I

3:32

I.Tr.I

12:23

II.Tr.E

1:43

I.Tr.I

8:57

4:39

I.Sh.I

14:45

II.Sh.E

2:57

I.Sh.I

14:13

II.Ec.R

5:42

IV.Sh.E

0:05

IV.Oc.D

3:58

I.Tr.E

20:35

III.Oc.D

23:57

III.Oc.R

May 15

May 22
May 23

5:47

I.Tr.E

2:40

I.Oc.D

5:11

I.Sh.E

6:53

I.Sh.E

3:14

IV.Oc.R

6:24

II.Oc.D

7:05

II.Tr.I

6:08

I.Ec.R

9:18

IV.Tr.I

May 31

0:55

I.Oc.D

1:48

III.Ec.D

9:24

II.Sh.I

12:00

IV.Ec.D

11:38

II.Ec.R

4:27

I.Ec.R

9:53

II.Tr.E

14:17

IV.Ec.R

12:28

IV.Tr.E

4:59

III.Ec.R

12:09

II.Sh.E

0:48

I.Oc.D

4:13

23:51

I.Tr.I

16:41

III.Oc.D

17:23

IV.Oc.D

1:02

I.Sh.I

20:03

III.Oc.R

20:38

IV.Oc.R

I.Ec.R

2:06

I.Tr.E

21:22

IV.Sh.I

22:05

I.Tr.I

22:00

I.Tr.I

3:16

I.Sh.E

21:49

III.Ec.D

23:20

I.Sh.I

23:07

I.Sh.I

3:54

II.Oc.D

23:01

I.Oc.D

0:14

I.Tr.E

9:03

II.Ec.R

23:34

IV.Sh.E

May 16

Every day, interesting events happen between Jupiter's satellites and the planet's disk or shadow. The ﬁrst columns give the date and
mid-time of the event, in Universal Time (which is 4 hours ahead of Eastern Daylight Time). Next is the satellite involved: I for Io, II
Europa, III Ganymede, or IV Callisto. Next is the type of event: Oc for an occultation of the satellite behind Jupiter's limb, Ec for an
eclipse by Jupiter's shadow, Tr for a transit across the planet's face, or Sh for the satellite casting its own shadow onto Jupiter. An
occultation or eclipse begins when the satellite disappears (D) and ends when it reappears (R). A transit or shadow passage begins at
ingress (I) and ends at egress (E). Each event is gradual, taking up to several minutes. Predictions by IMCCE / Paris Observatory.

Sk yandTelescope.com May 2016

51
http://www.imo.net/visual/major http://www.is.gd/ThetaVirMay2016 http://www.SkyandTelescope.com
Sky and Telescope - May 2016

Table of Contents for the Digital Edition of Sky and Telescope - May 2016
