أتمنى تساعدوني ..

[الفلك]

السلام عليكم
لو سمحتو عندي أسئلة كثيرة أتمنى تساعدوني في حلها :(
وبأسرع وقت

1. What is the order of planets as we move away from the Sun?
2. What is the distance between the Sun and Mercury in AU?
3. What is the distance to the nearest star in ly? In pc?
4. What is the distance to the Andromeda Galaxy in ly? In pc?
5. What is the angular diameter of the Moon in degrees?
6. What is the angular diameter of the Sun in degrees?

[ارخميدس12]

1. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
2. Mean distance of Mercury from Sun: 0.387 AU = 5.79x10^7 km
3. The star nearest to the Sun is Proxima Centauri. Proxima Centauri is 4.3 light-years from the Sun.
4. The distance to the Andromeda Galaxy is 2.54 million light-years
5. Since 1 radian = 57.3 degrees, the angular radius of the Moon is 0.0045 x 57.3 = 0.26 degrees, so its diameter is 0.52 degrees
6. The Sun has an angular diameter of about ½ degree

و الله أعلم .. جميع الإجابات بالإعلى منقولة بمساعدة العلامة قوقل !! و تقبل تحياتي

[فراج]

pc = 3.2615 LY ; proxima centauri is 1.31841774 pc from the sun
the distance to the andromeda galaxy is 778.782 pc
the angular diameter of the sun = 1/2 degree
the angular diameter of the moon = 1/2 degree
الاجابات التي اوردها ارخميدس 12 صحيحه انا اضفت فقط المسافه بال بالبارسك وهي مطلوبه بالاسئله .

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يسلموووووو الله يعطيكم ألف عافية

[الفلك]

7. Be able to work with the small angle formula
8. Be able to work with angles in arc sec, arc min, and degrees.
9. What causes the seasons on Earth?
10. What is the altitude of the North Star in Riydah? On the Equator? At the North Pole?
11. What are circumpolar constellations?
12. What is the ecliptic?
13. What causes the Moon to go through phases?
14. When does a total lunar eclipse occur?
15. What happens during a total lunar eclipse?

[فراج]

circumpolar constelations
In astronomy, the circumpolar constellations are constellations that never set from the viewer's perspective. Considered a very important effect in astronomy, it is different from seasonal constellations. Circumpolar constellations stay in the sky.

Because of the rotation of the Earth and its orbit around the Sun, we divide the stars and constellations into two groups. Some stars and constellations never rise nor set, and they are called circumpolar. All the rest are divided into seasonal stars and constellations. Which stars and constellations will be circumpolar and which seasonal depends on your latitude. In the northern hemisphere, we will always be able to see stars and constellations in the northern circumpolar sky, while in the southern hemisphere, we will always be able to see stars and constellations in the southern circumpolar sky.

The celestial north pole, currently marked by Polaris, always has an azimuth equal to zero. Also, its altitude for a given place is fixed and its value is given by the following formula: A = 90-Ø. All stars with a declination less than A are not circumpolar.

They are also visible year round at that location. From the North Pole, all constellations north of the celestial equator, (all fully visible constellations) are circumpolar, and similarly from the South Pole. From the equator, there are no circumpolar constellations. From mid-north latitudes (40–50°N), circumpolar constellations may include Ursa Major, Ursa Minor, Draco, Cepheus, Cassiopeia and the not well known Camelopardalis.
منقول من ويكيبديا

انظر الرابط التالي :
http://kvmagruder.net/bcp/diurnal/circumpolar.htm

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Ecliptic
The ecliptic is the apparent path of the Sun on the celestial sphere as seen from the Earth's center, and also the plane of this path, which is essentially coplanar with the orbit of the Earth around the Sun.[1] The path of the Sun is not normally noticeable from the Earth's surface because the Earth rotates, carrying the observer through the cycle of sunrise and sunset, obscuring the apparent position of the Sun against the background stars. Put simply, the ecliptic is the plane of Earth's orbit around the Sun.
منقول من ويكيبيديا

انظر الرابط التالي :
http://earthsky.org/space/what-is-the-ecliptic

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When does a total lunar eclipse occur ?

A total lunar eclipse can be observed at night and during Full Moon when

the Moon is near one of its orbital nodes so Sun, Earth and Moon form a straight line
and the observer is located on the night side of Earth

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what happens during a total lunar eclipse ?
Earth's shadow falls on the moon. The Earth is actually passing between the Sun and the Moon, blocking the sunlight that would normally be reflected off the lunar surface.

As the Moon passes into the shadow of the Earth, all of part of it becomes dark. But there is still some sunlight refracted by the Earth's atmosphere that passes into the shadowed area. This often causes the Moon to appear a deep red color during a total lunar eclipse.

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13 ? What causes the Moon to go through phases
The moon, Earth, and sun are in constant motion--the moon around the Earth and the Earth around the sun. When we face the sun, we see light. When we don't face the sun, we see darkness

Add the moon into this: the moon does not have its own light--it only reflects the sun. So like Earth, it has a face of light and darkness based on the sun's position relative to it. The amount of light we see "emitting" from the moon from our vantage point on Earth is based on the moon's relative position to the sun, which is in a constant cycle. So every 29.5 days (a lunar month), we see the same phases.



Imagine a soccer ball hung in the middle of a dark room at about the level of your head. Now imagine a flashlight shining on it from the side. Half is lit up, and half is in shadow. Now imagine walking around the soccer ball. When the ball is between you and the flashlight you can only see the shaded side. When you are between the ball and the flashlight the whole ball appears to be lit up.
The soccer ball is the moon. The flashlight is the sun. You are the Earth. Of course the moon goes round the earth, but the principle is the same.
Because of the way it orbits and the angle at which it is pointing towards the sun

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whate causes seasons on earth ? 9
The Earth is tilted on its axis. 'Summer' (the warmest season) occurs when a hemisphere, either the northern hemisphere or the southern hemisphere, is tilted towards the Sun and thus receives more direct sunlight (the Sun is closer to the zenith and is above the horizon longer). A common misconception is that the seasons have to do with the Earth being closer to the Sun due to the elliptical nature of its orbit. The orbit is elliptical and the Earth is closest to the Sun [aphelion] in early January, farthest away [perihelion] in early July) this has a minor effect on the seasons, more important is the number of days and weeks the Sun is higher in the sky; near perihelion for the northern hemisphere (although the Sun is further away) the atmosphere has the opportunity to heat up more.

Twice during the year (spring and fall Equinox - around the 20th of March and September respectively), the Sun appears to circle more directly over the equator [the axis of the Earth is in a plane perpendicular to the orbit], and most areas of the globe receive similar amounts of daylight (the poles are exceptions with extremely long periods of the sun either above or below the horizon. From late December to late March, the Southern Hemisphere experiences 'summer' while the Northern Hemisphere experiences 'winter'. From late June to late September, the position is the other extreme, and it is summer in the Northern Hemisphere, winter in the Southern.

These yearly changes in insolation (incoming energy from the Sun) cause the seasons, in conjunction with the prevailing directional wind patterns, ocean areas, currents, and pressure systems which all affect the local climate.

[الفلك]

يسلمووووووووو خيووووو الله يعطيك ألف عاااافيه
ساعدتني كثير ربي يوفقكك

[فراج]

العفو مع اطيب التمنيات بالتوفيق

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Be able to work with angles in arc sec, arc min, and degrees
تعريفات وتحويلات هامه
----------------------------
الدرجه القوسيه arc degree تساوي 60 دقيقه قوسيه
والدقيقه القوسيه arc minute تساوي 60 ثانيه قوسيه
والثانيه القوسيه arc second تساوي 60 ثانيه قوسيه
والثانيه القوسيه = 1 فرسخ نجمي او فلكي parsec
الفرسخ الفلكي parsec يساوي 3.2615 سنه ضوئيه light year
والثانيه القوسيه هي زاويه اختلاف المنظر او التزييح parallax في مدار الارض حول الشمس بالنسبه للنجم
ال parallax يعني اجراء عمليات الرصد الفلكيه لجسم سماوي معين من مكانين مختلفين على سطح الارض . وقد يكون ذلك بواسطه مرصدين بعيدين حيث تحسب الزاويه بينهما وبين النجم . او بعد سته اشهر عندما تكون الارض في الجانب الاخر في مدارها حول الشمس

-- البارسك او الفرسخ النجمي او الفلكي-- parsec -- pc
= ثانيه قوسيه واحده
= 3.2615 سنه ضوئيه
= 19.2 ترليون ميل ,, الف الف مليون ميل ,, اي 12 صفر
= 30865 الف مليون كيلو متر
= 206.265 وحده فلكيه AU
والكيلو بارسك يساوي الف بارسك والميجابارسك يساوي مليون بارسك

الراديان ,, وحده مقاييس قوسيه فلكيه radian تساوي
57 درجه 17 دقيقه و 44.6 ثانيه قوسيه

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الوحده الفلكيه Astronomical unit = المسافه بين الارض والشمس ويرمز لها بالاحرف AU
= 149.6 مليون كيلومتر
= 93 مليون ميل
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السنه الضوئيه ,, مقياس للمسافات ,, ,, Light year ,, LY
= 9461 الف مليون كيلو متر
= 5880 الف مليون ميل
= 63.240 وحده فلكيه AU
= 0.3066 من البارسك
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الميل Mile
= 1609.5 متر
= 1.609 كيلومتر

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الكيلومتر kilometer
= 1000 متر
= 0.621 من الميل

[فراج]

Be able to work with the small angle formula
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انظر الرابط التالي :
http://astro.physics.uiowa.edu/ITU/glossary/small-angle-formula/

والرابط التالي ايضا :
http://astronomyonline.org/science/smallangleformula.asp

[فراج]

اختلاف المنظر ( التزييح ) parallax
---------------------------------------------
انظر الرابط التالي :
http://imagine.gsfc.nasa.gov/YBA/HTCas-size/parallax3-derive.html

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يسلمو خيو على هالمعلومات يعطيك ألف عافيه

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يسعد مسائكم جميعا
لو سمحتوا أبغى أعرف الفرق بينهم بالعربي وبإختصار
76. What are emission nebulae? Reflection nebula? Dark Nebula?