Light, distance, mass — what can be worked out from what arrives.
Practise this list
From these 41 words, as many per round as you like — up to all of them: first what is due today, then new ones. First you choose, then you fill the gap, then you write it yourself. Mistakes come back again shortly.
More about this list
The twenty-fifth entry is a zona habitável, and English has two names for it where Portuguese has one. The formal one, « the habitable zone », matches the Portuguese word for word. The other comes out of a nursery tale. « The Goldilocks zone » is what a newspaper, a television programme and a good many textbooks will call it, after the child in the story of the three bears who tastes the porridge and finds one bowl too hot, one too cold and one just right. That is the whole argument in three bowls: too near the star and the water boils away, too far and it freezes, and only a band in between leaves it liquid, which is what the sentence on this page says. The figure has since walked out of astronomy. « A Goldilocks economy » is one growing neither fast enough to overheat nor slowly enough to stall, and « the Goldilocks principle » names any rule of thumb that asks for the middle of three. Portuguese tells the same tale and has built nothing on it: a zona habitável is named for what it allows, not for a child at a table.
A luminosidade de uma estrela não depende da distância a que está.The luminosity of a star does not depend on how far away it is.
a paralaxethe parallaxNoun (f)C2
A paralaxe mede-se ao longo de meio ano.The parallax is measured over half a year.
a vela-padrãothe standard candleNoun (f)C2
Uma vela-padrão tem luminosidade conhecida.A standard candle has a known luminosity.
a escada de distânciasthe distance ladderNoun (f)C2
Cada degrau da escada de distâncias é calibrado pelo anterior.Each rung of the distance ladder is calibrated against the one below.
a risca espetralthe spectral lineNoun (f)C2
Cada risca espetral pertence a um elemento.Every spectral line belongs to an element.
a fase de queima do hidrogéniothe hydrogen-burning phaseNoun (f)C2
A fase de queima do hidrogénio é a mais longa da vida de uma estrela.The hydrogen-burning phase is the longest in the life of a star.
a nucleossíntese estelarstellar nucleosynthesisNoun (f)C2
A nucleossíntese estelar produz os elementos mais pesados.Stellar nucleosynthesis makes the heavier elements.
a fase de gigante vermelhathe red giant phaseNoun (f)C2
A fase de gigante vermelha começa quando o hidrogénio acaba.The red giant phase begins when the hydrogen runs out.
a explosão por colapso do núcleothe core-collapse explosionNoun (f)C2
A explosão por colapso do núcleo dura poucos segundos.The core-collapse explosion lasts a few seconds.
a estrela de neutrõesthe neutron starNoun (f)C2
Uma estrela de neutrões cabe dentro de uma cidade.A neutron star would fit inside a city.
a massa não luminosathe non-luminous massNoun (f)C2
A massa não luminosa nota-se pelo que puxa.Non-luminous mass gives itself away by what it pulls.
a curva de rotação de uma galáxiathe rotation curve of a galaxyNoun (f)C2
A curva de rotação de uma galáxia não desce nas margens.The rotation curve of a galaxy does not fall off at the edges.
a radiação cósmica de fundothe cosmic background radiationNoun (f)C2
A radiação cósmica de fundo chega de todas as direções.The cosmic background radiation arrives from every direction.
a expansão do espaçothe expansion of spaceNoun (f)C2
A expansão do espaço afasta as galáxias umas das outras.The expansion of space drives the galaxies apart.
a zona habitávelthe habitable zoneNoun (f)C2
Na zona habitável a água pode ficar líquida.In the habitable zone water can stay liquid.
a curva de luzthe light curveNoun (f)C2
A curva de luz revela o tamanho do planeta.The light curve gives away the size of the planet.
a resolução angularthe angular resolutionNoun (f)C2
A resolução angular depende do diâmetro do espelho.The angular resolution depends on the diameter of the mirror.
a interferometriainterferometryNoun (f)C2
A interferometria junta vários telescópios num só.Interferometry joins several telescopes into one.
a ótica adaptativaadaptive opticsNoun (f)C2
A ótica adaptativa corrige o tremor do ar.Adaptive optics corrects the shimmer of the air.
as condições de observaçãothe observing conditionsNoun (f)C2
As condições de observação decidem a noite inteira.The observing conditions decide the whole night.
a radioastronomiaradio astronomyNoun (f)C2
A radioastronomia trabalha de dia e de noite.Radio astronomy works by day as well as by night.
a onda gravitacionalthe gravitational waveNoun (f)C2
Uma onda gravitacional estica e encolhe tudo o que atravessa.A gravitational wave stretches and squeezes everything it passes through.
a observação por vários canaisobservation through several channelsNoun (f)C2
A observação por vários canais junta a luz e as ondas do mesmo acontecimento.Observation through several channels puts together the light and the waves of one event.
a nuvem molecularthe molecular cloudNoun (f)C2
Dentro de uma nuvem molecular nascem estrelas novas.New stars are born inside a molecular cloud.
a ressonância orbitalthe orbital resonanceNoun (f)C2
A ressonância orbital mantém as luas em passo certo.Orbital resonance keeps the moons in step.
a velocidade de escapethe escape velocityNoun (f)C2
A velocidade de escape depende da massa e do raio.The escape velocity depends on the mass and the radius.