La observación astronómica incluye una estrella fugaz.

Because observación is a feminine noun in Spanish, so it takes la.

A useful clue is that many nouns ending in -ción are feminine:

• la observación
• la información
• la situación

So whenever you learn a noun ending in -ción, it is usually safe to assume it is feminine.

Because adjectives must agree with the noun they describe in gender and number.

Here, astronómica describes observación, which is:

• feminine
• singular

So the adjective must also be feminine singular:

• la observación astronómica

If the noun were masculine, you would use astronómico instead:

• el estudio astronómico

In Spanish, adjectives often come after the noun, especially when they are simply describing a category or type.

So:

• observación astronómica = astronomical observation

This is more natural in Spanish than putting the adjective first. English often puts adjectives before the noun, but Spanish usually does not.

Spanish uses the definite article more often than English does.

Here, la observación astronómica can refer to the activity or concept of astronomical observation in a general sense. Spanish commonly uses el/la in that kind of statement.

Without la, the phrase might sound more like a title, heading, or note rather than a normal full sentence.

Incluye is the third-person singular present form of the verb incluir.

The subject is la observación astronómica, which is singular, so the verb must also be singular:

• la observación astronómica incluye

This means:

• includes
• does include

Some forms of incluir are:

• yo incluyo
• tú incluyes
• él/ella incluye
• nosotros incluimos

Because estrella fugaz is being presented as one unspecified thing included in the observation.

So una works like a/an in English:

• una estrella fugaz = a shooting star

If it were a specific one already known to the listener, Spanish could use la instead:

• la estrella fugaz

It literally looks like fugitive star or fleeting star, but the normal meaning is shooting star.

This is a fixed expression in Spanish:

• estrella = star
• fugaz = fleeting, brief, passing quickly

So together, estrella fugaz is the usual everyday way to say shooting star.

Because not all Spanish adjectives change form for masculine and feminine.

Fugaz is an adjective with the same form for both genders:

• una estrella fugaz
• un fenómeno fugaz

It only changes for number:

• una estrella fugaz
• dos estrellas fugaces

In everyday language, yes, that is what people say. But scientifically, a shooting star is not actually a star.

In Spanish, just as in English, estrella fugaz is the common everyday term, even though the real phenomenon is usually a meteor.

So:

• everyday Spanish: estrella fugaz
• more scientific term: meteoro

Because the personal a is mainly used with people and sometimes animals or personified beings, not with ordinary objects or phenomena.

Here, una estrella fugaz is a thing, so no a is used:

• incluye una estrella fugaz ✅

Compare:

• Veo una estrella fugaz = I see a shooting star
• Veo a María = I see María

Yes. Depending on context, incluye can mean:

• includes
• contains
• features
• involves

In this sentence, includes is the most direct translation, but the exact English wording could vary a little depending on the context.

It follows a very common Spanish pattern:

• Subject + Verb + Object

So here:

• La observación astronómica = subject
• incluye = verb
• una estrella fugaz = direct object

This is straightforward and neutral word order in Spanish.

The stress is on the last syllable because of the written accent:

• ob-ser-va-CIÓN

The accent mark in -ción tells you where the stress goes.

This ending is very common in Spanish, and it is usually pronounced like:

• -thyon in much of Spain
• -syon in many other Spanish-speaking regions

So in Spain, observación is typically pronounced approximately:

• ob-ser-ba-THYON

Yes. That would mean Astronomical observation includes shooting stars or includes shooting stars in a more general plural sense.

The original sentence with una estrella fugaz refers to:

• one shooting star
• an example of a shooting star
• a single instance

The plural version sounds more general or broad.