Hubble’s Picture of the Week: Standard Candles in Popular Galaxy

Key Takeaways

1. NGC 3370 is a spiral galaxy located about 90 million light-years away in the constellation Leo.
2. New Hubble Space Telescope observations show clusters of blue stars, a yellowish-white core glow, and dark reddish dust strands.
3. The galaxy is significant due to the presence of Cepheid stars and type Ia supernovae, which help measure distances to galaxies.
4. Cepheid stars pulsate and their brightness helps estimate their distance from Earth.
5. Type Ia supernovae provide measurements of distance and help determine the Universe’s expansion rate.

Astronomers have shown a long-standing fascination with NGC 3370, a spiral galaxy situated approximately 90 million light-years away in the constellation Leo, often referred to as The Lion. They have conducted multiple observations of this galaxy over the years.

New Observations

A Hubble Space Telescope image of NGC 3370 was previously shared in 2003, but this latest observation brings additional insights. It captures light wavelengths that were absent in the earlier image.

The current image reveals clusters of blue stars scattered throughout the galaxy’s spiral arms. At the galaxy’s core, there is a striking yellowish-white glow. Dark reddish dust strands can be seen swirling around the center. In the backdrop, two medium-sized galaxies along with several smaller distant ones are visible.

Importance of NGC 3370

Though NGC 3370 boasts many striking features, its significance stems from the presence of Cepheid stars and type Ia supernovae. These celestial objects are crucial for astronomers as they help determine the distance to galaxies.

Cepheid stars are variable stars that pulsate in a radial manner. Their brightness and size fluctuate. By observing the duration of their pulsation, astronomers can estimate a Cepheid star’s luminosity. By comparing this brightness to how dim it appears from Earth, they can figure out its distance.

Type Ia supernovae represent the explosive end of a white dwarf star in a binary system. By measuring their brightness, astronomers can ascertain how far away they are. Hubble’s law indicates that galaxies that are farther away from Earth are moving away more quickly, allowing astronomers to determine the rate of the Universe’s expansion.

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