#AstroMiniBR: Why are there stars on the Brazilian flag?

In weekly publications, Technology World and #AstroMiniBR, twitter profile Choose from five space-related curiosities that bring together astronomers and astronomy advocates. Check out this week’s highlights below!

#1: The sky of the national flag

Did you know that the sky visible on our flag is the Proclamation Day of the Republic (15 November 1889)?

But the sky seen on the flag is inverted, as if we were looking from outside the celestial sphere.#AstroMiniBR pic.twitter.com/X8Bv9TXnQe

— Mirian Castejon?? (@MirianCastejon) 15 November 2022

Last Tuesday was a national holiday. November 15 celebrates an important event in Brazilian history: the Proclamation of the Republic. But what does that have to do with astronomy?

The relationship is actually indirect and appears in the Brazilian flag, the ultimate symbol of the nation’s representation on the planet. Flag of Brazil with a white stripe in the middle that reads “Ordem e Progresso”, in addition to the traditional shapes of the green rectangle, yellow diamond and sky blue sphere it also has 27 stars representing the country’s 26 states and Federal District.

The current version of the flag was introduced just 4 days after the proclamation of the Republic, replacing the old imperial flag. However, this first version had only 21 stars representing states at the time. Amapá took the form we all know it in 1992, adding stars that refer to the new states of Tocantins, Roraima and Rondônia.

The arrangement and size of each star was determined from the sky view of the city of Rio de Janeiro on the night of November 19, 1889, and the only remaining star above the white band, the country’s motto, is the symbol of the star Spica, representative of the state of Pará, then the largest region after Ecuador.

#2: Before and After James Webb

Before/After JWST ??

This L1527 is a newborn system containing a young star and a protoplanetary disk of gas and dust.

This double cone structure is the outflow caused by the star’s recent collision with the interstellar medium.#AstroMiniBR pic.twitter.com/74jIOiHDap

— Camila Esperanca (@astronomacamila) 16 November 2022

The image you see in the upper right was released by NASA last Wednesday (16) and contains a protostar inside a dark cloud known as L1527, hidden in this cosmic hourglass-shaped narrow region.

The most striking aspect of this image, taken with NASA’s James Webb Space Telescope Infrared Camera (NIRCam) imaging instruments, are the blue and orange clouds that line the gaps formed when material collides with the protostar. surrounding matter. The blue areas represent the region where the dust is thinner, and the orange areas represent the thickest dust layers.

Despite the chaos that is the nature of the L1527 system, it is an astronomically young celestial body: only 100,000 years old. For this reason, L1527 is considered an early stage of star formation. Still encapsulated in a dark cloud of dust and gas, protostars like this have a long way to go before they become main-sequence stars like our Sun.

#3: Know the Solar Analemma

analemmas are images that accompany the movement of a celestial body.

this is always made at 16:45 from the Sicily/Italy region and ? What the Sun did for 1 year by emphasizing the solstice and equinox dates#AstroMiniBR
{c} @enrosadire pic.twitter.com/QMcF3lhkGb

— yanna martins franco (@martins_yanna) 15 November 2022

If you looked at the sun from the same place at the same time every day, would it appear in the same place in the sky? We don’t need much astronomy knowledge to answer no. Indeed, the answer would be yes if the Earth did not have a tilted axis of rotation and its orbit around the Sun was perfectly circular. However, its tilt of 23.5 degrees from Earth and the fact that its orbit is slightly elliptical creates a figure-8 pattern where the Sun will appear at the same time point throughout the year.

This pattern is called analemma. During the summer the Sun will appear at its highest point in the sky – and therefore at the highest point of the analemma. In winter, the sun will be at its lowest point. Intermediate locations form the rest of the analemma pattern and will travel to different latitudes of the Earth.

#4: James Webb Space Telescope and Infrared Universe

The JWST telescope has come to revolutionize our knowledge of infrared astronomy!

Below are the creation columns observed by HST and JSWT.

You can compare, just access https://t.co/f9pQa4RWmG.#AstroMiniBR #SemanaThematica #Infrared pic.twitter.com/TMf8pkTURN

— Camila Esperança (@astronomacamila) 8 November 2022

The beautiful recording above was made by the team of astronomers from the Deep Sky Project and includes the famous Horsehead Nebula. Its dark features are due to the opaque dust cloud lying in front of the bright red emission nebula.

Over thousands of years, the internal movements of this cloud will change its appearance and the reference will be lost due to the pareidolia done by us humans. The red color of this record is attributed to the recombination of electrons with protons to form hydrogen atoms.

#5: Observing the feeding of supermassive black holes

Infrared observations allow us to understand that supermassive black holes are feeding!

At the core of galaxy NGC 4111, a ring of hydrogen (H2) gas with a radius of ~360 light-years feeds the supermassive black hole at its center.#AstroMiniBR pic.twitter.com/SpHMQ6LHLN

—Gabriel Roier???? (@gabe_roier) 11 November 2022

Among the numerous advantages of looking at the universe at infrared lengths is the ability to analyze in detail the dynamics of central black holes in distant galaxies.

The above image shows the galaxy NGC 4111, located about 50 million light-years from Earth in the constellation Canes Venatici. It’s a lenticular galaxy that isn’t exactly a peaceful place, as it might seem at first glance.

At its center is a series of fibers that stand out against the bright core of the galaxy. Astronomers believe these filaments are made of dust associated with a ring of material that surrounds and feeds the supermassive black hole in the galaxy’s core.