#AstroMiniBR: Scientists also use filters to photograph galaxies

In weekly publications, Technology World this #AstroMiniBRA Twitter profile that brings together astronomers and astronomy supporters, it brings together five related curiosities about space. Check out this week’s highlights below!

#1: How many decimal places of pi will be used?

NASA uses a 15-digit approximation to the pi number (π = 3.141592653589793) for space mission calculations.

With 40 digits, it is possible to calculate an inaccurately observable universe-sized environment smaller than a hydrogen atom.#AstroMiniBR pic.twitter.com/7y3ntayQsn

— Nicolas Oliveira (@nicooliveira_) December 7, 2022

Everyone remembers this information from basic math: pi is an irrational number defined by the ratio between the circumference and diameter of a circle, which is approximately 3.14.

Since the number pi represents an infinite string of digits, it can be expressed indefinitely according to one’s interest in achieving a particular result. For example, world record holders have perfectly memorized the order of more than 70,000 digits in the decimal places of pi.

However, this absurd level of rigor is unnecessary for the absolute majority of mathematical procedures that require an approximation of its value. High-precision calculations, such as those used by NASA for interplanetary navigation, use about 15 decimal places: 3.141592653589793. Actually, you don’t need to use any more decimal places than that. This is because scientists do not perform physically realistic calculations, which must include as many decimal points as the mind can imagine.

Proof of this is that Voyager 1, the farthest spacecraft from Earth, is about 24 billion kilometers away from us; If we wanted to construct a circle taking this distance as a radius using a 15 digit pi value, the error of this measurement would be less than 1 centimeter. If we were ambitious and wanted to encompass the entire visible universe, we could only use 40 numbers, and that error would be smaller than the diameter of a hydrogen atom!

#2: Tycho crater as seen by Orion

??PHOTO OF THE WEEK??
As the Orion spacecraft begins its return journey to Earth, the Moon’s transit is scheduled to crash into the Pacific Ocean on 12/11. The ray crater Tycho is highlighted. #AstroMiniBR pic.twitter.com/04JteD5SfC

— The Deep Sky Project (@CeuProfundo) December 6, 2022

NASA’s Orion spacecraft is ending its landing mission far from Earth: the probe, designed to take astronauts to the Moon, has performed a series of maneuvers and tests in lunar orbit and is now on its way back to Earth, where it is expected to crash. Pacific Ocean on Sunday (11).

On this short and impressive journey, Orion recorded the lunar surface in incredible detail: the video above shows one of the last close passes before the return; the meteorite that formed it. In general, these striated craters are relatively young and range from several tens to several hundred kilometers wide.

#3: Beautiful Shrimp Nebula

SHRIMP NEBULA

ESO’s 2.2m telescope in Chile captured one of the best images of this stellar nursery.
This nebula is 6000 light-years away in the constellation Scorpio and we can see newborn stars through the clouds.#AstroMiniBR
© ESO pic.twitter.com/q8Appfbpud

— Thiago Flaulhabe (@TFlaulhabe) December 3, 2022

South of Antares, in the tail of the constellation Scorpius, is the emission nebula known as the Prawn Nebula (IC 4628), which is rich in nebulae. Countless hot, massive young stars, only a few million years old, are stripping electrons from atoms by irradiating the nebula with invisible ultraviolet light. These electrons eventually recombine with other atoms to produce the nebula glow we see in the image above, dominated by red emission from hydrogen.

Located an estimated 6,000 light-years from Earth, the region spans about 250 light-years, equivalent to three full moons in the sky. This stunning image was taken with the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile and is one of the best images of this object to date.

#4: Why observe celestial bodies in different filters?

an example of the importance of observing the same object at various frequencies

galaxy NGC 628 (seen here by radio)@almaobs) near ultraviolet (@AstroSat3 and in infrared, @NASAWebbdo we see bubbles in the interstellar medium of this galaxy????#AstroMiniBR pic.twitter.com/VtSHbKp7vv

— yanna martins franco (@martins_yanna) December 5, 2022

In modern astronomy, it is common to observe the same celestial body under different filters and combine this data to achieve better scientific results. Unlike previous decades, when astronomers mainly studied at a specific wavelength such as radio, optics or X-ray, today’s observations have the advantage of detecting physical structures and processes that are impossible for some individual filters.

Because the physics driving the evolution of celestial bodies such as stars and galaxies is complex, combining observations of the same object at various wavelengths allows astronomers to better understand the associated physical processes. For example, the galaxy above may look ordinary in visible light, but the same object shows a series of bubbles in the infrared, possibly caused by high-energy phenomena.

#5: A Brazilian radio interferometer

BDA – Brazilian Decimetric Array – is an interferometric experiment consisting of 26 antennas with a diameter of 4 meters. It is set in Cachoeira Paulista and its main target is the Sun. #AstrominiBR pic.twitter.com/jrfk5bindm

– Tania Dominici (@TaniaDominici) December 8, 2022

The Brazilian Decimetric Array (BDA) is a Brazilian radio interferometer installed at INPE in Cachoeira Paulista, São Paulo, which has been in operation since late 2004. BDA has five antenna prototypes using modern and economical interferometry techniques in the radio band. Obtaining high spatial and temporal resolution images of the Sun. It can produce ten images of the Sun per second and perform an analysis in real time using spectral tomography techniques. It is also expected to improve space weather forecasting with the BDA.