Guidance of Pleiades watching
1. Background
Pleiades is a group of many stars which locates at constellation of Taurus. You can see 6-7 stars in thecluster with the naked eyes. From ancient times, people have noticed this tight group of stars. Variouscultures have diﬀerent names of Pleiades.
Galileo observed the Pleiades with his telescope. Though his telescope had a far poor performance
than modern telescopes of the similar size, Galileo could conﬁrm 36 stars in the Pleiades.
The stars in the Pleiades were born at the almost same time (about 100 million years ago) in a same interstellar gas cloud. Meanwhile the Sun is 4.6 billion years old. Compared with the Sun, the stars in the Pleiades arevery young.

2. Purpose
The aim of this activity is that children experience the feeling of wonder that Galileo had when heobserved celestial bodies for the ﬁrst time. When children observe the Pleiades with a telescope, they will
notice that there are many stars in the area. Teachers make children do sketch of the Pleiades by themselves
and lead them to ﬁnd many stars in the ﬁeld of view.

3. Observation Tips
It is not diﬃcult to see the Pleiades with a low magniﬁcation telescope. As for the person who use telescope
for the ﬁrst time, it is advisable to have a practice session by using distant scenery in daytime.

4. Steps(a) Observation and sketch with the naked eyes
The Pleiades locates at the constellation of Taurus. If you cannot ﬁnd Pleiades directly, search the westof Orion.
For observation and sketch, you use the ﬁrst sheet. Children count the number of stars in Pleiades withthe naked eyes, and write it in the frame of the worksheet. The person who has poor eyesight see Pleiades likea cloud.
(b) Observation and sketch with the telescope
You use the second sheet for observation and sketch with the telescope. Enter the Pleiades in the ﬁeldof view of the telescope, then sketch it. Children would see many stars there. For a comparison, enter a brightstar such as Sirius in the constellation Canis Majoris in the ﬁeld of view, children will notice fewer stars than in
Pleiades area.
Magniﬁcations of the telescopes are as follows:
For Hoshi-no-Techou Inc. telescope kit, the magniﬁcation is a 15 power(Focal length of the telescope is 273mm and focal length of the eye piece is 18.2mm).
For ORBYS Inc. telescopes kit, it is a 35 power(Focal length of the telescope is 420mm and focal length of the eye piece is 12mm).
(c) Write any ﬁndings and/or questions
Write anything you found out and/or question from your observations in your sketch sheet under thesketch column.
(d) Think why some stars make a group, why some stars exist alone like the SunChildren think why stars are in a group by seeing the photo or the Galileo's sketch of Pleiades on thework sheet of the post observation study.
Summarize your knowledge of the Pleiades, which you learned from observations with the telescope
and through a text book or the internet. Also, write down what you want to know more and what you can dofurther.

5.Notes
In this activity, children notice that Pleiades is actually a star cluster and more stars can be seen
there when we use telescope. In addition, children think why some stars make a group and others don't.
Teacher will explain the star formation mechanism and its evolution, depends on children's levels ofunderstanding.
If it is possible, teachers observe Pleiades with a larger telescope beforehand. If the sky condition isgood, you can see a bright nebula around Merope with a 10cm (or larger aperture) telescope.
On the photo, you can clearly see a pale nebula. This nebula is called IC349. It is one of the diﬀuse nebula,
it reﬂects starlight from nearby stars, Merope and others. This nebula is temporally located near Merope atpresent time. It is not associated with the stars of Pleiades.

Caution must be given to children that "Never watch the Sun through the telescope!”