IOAA 2014, Анализ на данни · окончателна тема — Задача 3. IOAA Observer on an extrasolar planet

8th IOAA · Final data analysis paper

Внимание: Бележка към темата

The final paper is preserved in six photographed sheets. Its three whole problems differ from the preliminary solution booklet: Black Hole is renumbered, Thermodynamic test is separate, and the observer problem replaces seven Big Dipper stars with four Mizar-system stars and adds uncertainty estimates. Applicable key material is distinguished from variant comparisons; absent final-key portions and the missing orbit-plot annex are explicit.

Условие

The Sirius star, located in the constellation of Canis Major, is the brightest star in the night sky of the Earth. What the observer's eye sees as a single star is actually a binary star system.
The high brightness of Sirius is a consequence of two facts: its intrinsic luminosity and its proximity to the Earth.
The Mizar multiple star system, in the constellation of Ursa Major, consists of 4 stars seen along the same line of sight from the Earth. Some of these stars form a gravitationally bound system.
Let's assume that an observer (observer A) is located on one of the planets of the Sirius system.

Determine:

a)

The magnitude of the Sun as seen by observer A (mSun,Planetm_{\text{Sun,Planet}}).

b)

The magnitude of Sirius star system as seen by the observer A (mSY,Planetm_{\text{SY,Planet}}).

c)

The combined intrinsic luminosity of the Mizar system, LMizarL_{\text{Mizar}}.

d)

The average distance between gravitationally bound stars of the Mizar system and Earth.

e)

The geocentric angular distance between Mizar system and Sirius, Δθ\Delta\theta.

f)

The physical distance between the gravitationally bound stars of the Mizar system and the observer A (dMizar,Planetd_{\text{Mizar,Planet}}).

g)

The magnitude of the entire Mizar system as seen by the observer A (mMizar,Planetm_{\text{Mizar,Planet}}).

Also estimate amount of errors in all your answers.

Data

The following data may be used:

  • dSirius,Earth=2.6 pcd_{\text{Sirius,Earth}}=2.6\,\mathrm{pc} – the Sirius–Earth distance;
  • mSirius,Earth=−1.46mm_{\text{Sirius,Earth}}=-1.46^{\mathrm m} – the apparent magnitude of Sirius measured from the Earth;
  • dSun,Earth=1 AUd_{\text{Sun,Earth}}=1\,\mathrm{AU} – the Sun–Earth distance;
  • mSun,Earth=−26.78mm_{\text{Sun,Earth}}=-26.78^{\mathrm m} – the apparent magnitude of the Sun as seen from Earth;
  • dSirius,Planet=10 AUd_{\text{Sirius,Planet}}=10\,\mathrm{AU} – distance between Sirius and its planet where the observer A is located.

In the table below information for the stars from the Mizar system as measured from the Earth is given.

Star numberName of the starApparent magnitudeParallax (mili arc seconds)
1Alcor3.99±0.013.99\pm0.0139.91±0.1339.91\pm0.13
2Mizar A2.23±0.012.23\pm0.0138.01±1.7138.01\pm1.71
3Mizar B3.86±0.013.86\pm0.0138.01±1.7138.01\pm1.71
4Sidus Ludoviciana7.56±0.017.56\pm0.018±48\pm4

The equatorial coordinates of Mizar system (σ1\sigma_1) and respectively of Sirius (σ2\sigma_2), located on the heliocentric map are:

αMizar=α1=13h23min55.5s;\alpha_{\text{Mizar}}=\alpha_1=13^{\mathrm h}23^{\mathrm{min}}55.5^{\mathrm s};
δMizar=δ1=54∘55′31′′;αSirius=α2=6h45min;\delta_{\text{Mizar}}=\delta_1=54^\circ55'31'';\qquad\alpha_{\text{Sirius}}=\alpha_2=6^{\mathrm h}45^{\mathrm{min}};
δSirius=δ2=−16∘43′.\delta_{\text{Sirius}}=\delta_2=-16^\circ43'.
Original celestial-coordinate diagram.
Original celestial-coordinate diagram.

Note

ln⁡(1−x)≈−xfor x≪1;ex≈1+xfor x≪1.\ln(1-x)\approx-x\quad\text{for }x\ll1;\qquad e^x\approx1+x\quad\text{for }x\ll1.

Решение

Внимание: Непълно решение

The available preliminary Problem 3B key uses seven Big Dipper stars, whereas the final photographed problem asks about four Mizar-system stars and uncertainties. No matching final key for c, d, f, g or the error estimates was found. The compatible Sun calculation and explicitly conditional earlier Sirius calculation are reproduced; the earlier angular calculation is identified as a source discrepancy.


Оригинал в Архива: ioaa11.jpg · официални решения: DA_Solution.pdf · допълнителни данни: ioaa12.jpg · допълнителни данни: ioaa13.jpg · допълнителни данни: ioaa14.jpg · допълнителни данни: ioaa15.jpg · допълнителни данни: ioaa16.jpg