Съдържание

IOAA 2025, Наблюдения, звездни карти (OM) — Задача 1. Know your Sky

Оригинал на условието (PDF)Съобщи за грешка

Всички материали от IOAA 2025

OM02: Solution and Marking Scheme · 16 т.

Условие

Use the skymap “Map-OM01” to answer the questions below.

(OM01.1) Mark all the objects listed below with a box (□) around the object. Label each of your marked objects with the corresponding Object No.

Object No.	Object Name	Object No.	Object Name
1	$\beta$ Aur	5	$\delta$ Gem
2	$\delta$ Cep	6	$\beta$ CVn
3	$\delta$ Cnc	7	$\alpha$ Lyn
4	$\delta$ Cet	8	$\beta$ Per

[4 т.]

(OM01.2) Mark the positions of the following 6 galaxies from the Messier Catalogue using a plus sign (+) and label them with their corresponding Messier number.
M32, M51, M74, M81, M94, M101 [6 т.]

(OM01.3) Draw the Ecliptic on the map and label it as “E”. [2 т.]

(OM01.4) A total solar eclipse occurred on 1 August 2008. At a certain place on Earth the totality occurred at local noon.

(OM01.4a) Mark the position of the Sun at the time of the eclipse with a cross ( $\times$ ) and label it as “S”. [1 т.]

(OM01.4b) Draw the Moon at the appropriate position on the map as seen from the same location on 28 July 2008 at local noon, and label it as “M”. The drawing should be of appropriate shape and orientation, but need not be to scale. The bright side of the Moon should be shaded. [3 т.]

Решение

(OM01.1)

Every correct star gets	0.5

(OM01.2)

Intersection point of each cross inside the inner circle	1.0
Intersection point of each cross between the inner and outer circles	0.5

(OM01.3)

The curve passes within the boundaries of 6 or 5 zodiacal constellations.	1.0
The curve passes within the boundaries of 3 or 4 zodiacal constellations.	0.5
Curve is completely inside the inner bounds.	1.0
$\geq 50\%$ of the curve is inside the bounds.	0.5

If the curve is clearly non-monotonic or not smooth, penalty of $-1.0$ mark.

(OM01.4a)

The date when the eclipse occurred is 1st August. During the start of the month of August the Sun is in the constellation of Cancer.

Position of Sun within the box.	1.0
Sun not on the Ecliptic irrespective of whether the Ecliptic is correctly drawn.	0.0
Position of Sun consistent with Ecliptic drawn in previous part and Sun is within Cancer but outside the box.	0.5

(OM01.4b)

28 July was 4 days before the eclipse occurred.

Moon moves around $13^{\circ}$ every day from west to east. Hence, Moon will be around $52^{\circ}$ to the east of Sun, almost along ecliptic, i.e. Moon will be in constellation of Taurus.
Phase of the Moon will be crescent (anything less than half is acceptable).
The bright part of the Moon should be towards the Sun.

Solution for (OM01.4b): the star map with the Sun region (cross labelled S) and a second shaded region to the right containing a crescent Moon labelled M.

Crescent of Moon drawn	0.5
Bright part is towards Sun	0.5
Any part of Moon drawing is within the box	1.0
Value of elongation of Moon and Sun, irrespective of position of Sun in the earlier part is around $\approx 52^{\circ}$ or $3.5\,\mathrm{h}$	1.0

Оригинал в Архива: Observation-SkyMap-Questions.pdf · официални решения: Observation-SkyMap-Solutions.pdf