Transcript Group competition

Group competition
Tonight:
• discussion
• translation
• printing
5 problems: (5 x 20 points)
1. Constellations
2. Orbital motion
3. Identifying telescope components
4. Minimum of an eclipsing binary
5. Nocturnal
1. Constellations + Messier’s
2. Orbital motion
A star of mass m moves around a star of mass M
in the indicated direction, where m << M.
The major axis of the ellipse is aligned with the
direction to the observer, and the motion of the
star is in the plane of the diagram.
3. Identifying telescope
components
4. Minimum of an eclipsing binary
The figure shows the secondary (shallower)
minimum of the light curve of an eclipsing binary
star. The difference between bolometric
magnitudes m1,Bol – m0,Bol = 0.33 magnitude.
We also know from simultaneous spectroscopy
that the star with the smaller radius was
eclipsed by the larger star during the secondary
minimum (since only one spectrum was
observable during the minimum).
Determine the change of brightness of this
binary during the primary minimum and draw the
shape of the primary minimum using the same
scale as the secondary minimum. Label the
graph with all appropriate parameters.
Use the answer sheets (one blank, one with the light curve plots)
for your final answers.
You may assume that the eclipses are central, that the stars are spheres of
constant surface brightness, and that the distance between the stars does not
change.
5. Nocturnal
Circumpolar stars describe a full circle around the Celestial Pole over 24 hours. This can
be used to make a simple clock.
You are given a blank card with a movable ring, along with a clear strip with a centre
circle. If the card has a suitable scale, the clear strip is attached as in the diagram below
and the Pole Star is visible through the centre circle, then the position of the star Kochab
(β UMi) on the inner edge of the ring will give the current time.
Design and mark on the card and ring suitable inner and outer scales (as required) such
that, in Katowice for any night of the year, the side of the clock marked “UT” can be
used to show current Universal Time, and the other side (marked “ST”) can be used to
show current Local Sidereal Time.
For 27 August in Katowice, the lower culmination of Kochab is at 05:15 Central European
Summer Time (UT+2). The coordinates of Kochab (β UMi) are : α: 14h 51m, δ: +74.2.
Notes:
– The blank card is marked with a line which should be held horizontally when the device
is used.
– The clear strip will be attached later, after you have finished and handed in the card.
For now it is left off so that it does not get in your way when making the scale.
Translation notes for leaders
1. Please do not translate 'COUNTRY NAME' at the top of
the page, but replace it with your country name in
English, e.g. 'POLAND'.
2. Please do not translate the IAU abbreviations in column
2 of the table in question 1. You may of course translate
the heading and the other columns as required.
3. In question 3, please do not change the 'M' in the
example ('Tripod'), as it refers to the label on the
photograph.
4. In question 4, you can change the labels on the
diagrams if necessary, but please do not change the size
or proportions of the diagrams.
reserve problem
Prepare a paper board to determine an angular
resolution of telescope (diameter = 8cm). Such
estimation can be done during the day before real
observations. Draw a schematic view of solar
system bodies such as planes, moons, Saturn’s
rings etc, in different distances from the Earth.
Check visibility of details on board located 20m
ahead from telescope and mark resolved pictures.
Assume that Earth orbit is circular (radius = 1AU)
Size (radius) [km]
Orbital radius
Mercury
2440
0.39 AU
Venus
6052
0.72 AU
Mars
3396
1.52 AU
Jupiter
69911
5.20 AU
Great Red Spot
6000  12000
Io
1,821
421700 km
Europa
1569
670 900 km
Ganymede
2634
1070400 km
Callisto
2410
1 882 700 km
60268
9.58 AU
Saturn
6630 km – 120700km
Ring
Titan
2576
1221870 km
Uran
25559
19.23 AU
Neptune
24764
30.1 AU
Sizes of pictures should be equal to real angular size of bodies in
extreme distance from earth.
Team will receive 1 point per each proper draw.