LUNAR PHASE

LUNAR PHASES & ECLIPSE

(চান্দ্রদশা ও গ্রহণ)

​

​

​

By

Chowdhury Tasneem Jahan Srabon

Dept. of Physics, University of Chittagong

LUNAR PHASES

(চান্দ্রদশা)

Apparent shape of the Moon’s illuminated portion as seen from Earth

​

The Moon is between the Earth and Sun, so the side facing Earth is dark.

A sliver of the Moon starts to become visible on the right side

The entire face of the Moon visible from Earth is fully illuminated.

More than half of the Moon is illuminated, approaching full

The illuminated portion begins decreasing, now on the left side.

Only a small crescent of light remains before the cycle starts again.

Half of the Moon’s disk is illuminated on the right side

Half of the Moon’s disk is illuminated on the left side

নতুন চাঁদ/অমাবস্যা

Moon

Moon

শুক্লপক্ষের সরু চাঁদ

প্রথম চতুর্থাংশ

তৃতীয়/শেষ চতুর্থাংশ

কৃষ্ণপক্ষের উজ্জ্বল চাঁদ

পূর্ণিমা

শুক্লপক্ষের উজ্জ্বল চাঁদ

কৃষ্ণপক্ষের সরু চাঁদ

ECLIPSE

(গ্রহণ)

​

A game of shadow

Only Earth, Sun and Moon can play this game.

Whereas you, me and the humanity enjoy

this heavenly game.

​

​

​

​

​

​

Solar Eclipse (সূর্যগ্রহণ)

In short, Moon blocks the Sun.

Lunar Eclipse

(চন্দ্রগ্রহণ)

Time for revenge!

Earth blocks the Moon this time.

Let’s see how the eclipses take place

• When sun, moon and earth appears in the same alignment, eclipses happen.
• When moon appears in between the sun and earth, solar eclipse happens.
• When earth appears in between the sun and the moon, lunar eclipse happens.

Types of Lunar Eclipses:

​

• Total Lunar Eclipse (পূর্ণ চন্দ্রগ্রহণ)
• Partial Lunar Eclipse

(আংশিক চন্দ্রগ্রহণ)

• Penumbral Lunar Eclipse

(উপছায়া চন্দ্রগ্রহণ)

Types of Solar Eclipses:

​

• Total Solar Eclipse (পূর্ণ সূর্যগ্রহণ)
• Partial Solar Eclipse (আংশিক সূর্যগ্রহণ)
• Annular Solar Eclipse (বলয়গ্রাস সূর্যগ্রহণ)
• Hybrid Solar Eclipse (হাইব্রিড সূর্যগ্রহণ)

Total Solar Eclipse

(পূর্ণ সূর্যগ্রহণ)

​

Sun is totally blocked by the moon. When the moon is at the perigee (অনুভূ), the umbral shadow is bigger. Thus, covers the whole sun. Interestingly, only sun’s corona is visible.

(আংশিক সূর্যগ্রহণ)

Annular Solar Eclipse

(বলয়গ্রাস সূর্যগ্রহণ)

​

When moon is at apogee(অপভূ),it can not shadow the sun totally.

Annular solar eclipse happens.

A ring(annulus) of fire is visible around the shadow.

Hybrid Solar Eclipse

(হাইব্রিড সূর্যগ্রহণ)

Hybrid Solar Eclipse happens when both total and annular solar eclipse occur in the same eclipse path.

This weird phenomena occurs because of earth’s curvature. When the moon is at the right distance from earth that earth’s curvature effects the eclipse, hybrid solar eclipse happens.

A transition from total to annular or annular to total solar elipse occurs during hybrid solar eclipse.

​

• Umbra means shadow. It is the dark shadowed region in the diagram. When the moon passes through the umbra, total lunar eclipse happens.

​

• Penumbra is the light shadowed region. When moon passes through the penumbra region, penumbral lunar eclipse happens.

​

• When part of the moon passes through the umbra, and the rest through the penumbra, partial eclipse happens.

THANK YOU