Hubble's updated view of NGC 3370, richer in light and detail than ever before, deepens our understanding of both the galaxy and the cosmos itself.
The updated picture of Hubble's image of NGC 3370, richer in light and detail than ever before, deepens our understanding of the galaxy and the universe itself.
This new Hubble image of the week highlights a galaxy that has been a favorite subject for more than two decades. This elegant spiral galaxy, called NGC 3370, lies about 90 million light-years from Earth in the constellation Leo. Over the years, Hubble has returned to it many times, capturing increasingly detailed images of the arms and bright central region.
Why do astronomers continue to study the NGC 3370
Why is NGC 3370 so important to scientists? The galaxy contains two types of celestial objects that are essential for measuring cosmic distances: Cepheid variable stars and Type Ia supernovae. Both act as "standard candles," allowing astronomers to calculate the distance to other galaxies with impressive accuracy.
Measuring the universe using pulsating stars
Cepheid variable stars expand and contract rhythmically, changing their size and temperature as they pulsate. This process causes their brightness to rise and fall in predictable cycles that last from days to months. The important insight is that the brighter a Cepheid is, the longer it takes for it to complete one full pulse. By timing these fluctuations in light and comparing the star’s true brightness to its apparent brightness from Earth, astronomers can determine its distance—and from it, its distance to its host galaxy.
Explosive clues from supernovae Ia
Type Ia supernovae provide another way to measure vast distances, but instead of regular pulses, they erupt in one spectacular explosion. These events occur when the dense core of a dying star suddenly ignites again in a burst of nuclear fusion. These supernovae reach nearly identical peak brightness levels, so astronomers can use them as benchmarks to determine their distance. Observations of Cepheid variables and Type Ia supernovae are essential to refining our understanding of how fast the universe is expanding.
Sharper and more detailed portrait
Hubble's previous image of NGC 3370 was published in 2003 (see above). In the newly revealed version, the lens has zoomed in closer, allowing for a much more complex view of the galaxy's spiral structure and star-filled regions. The latest image includes light at wavelengths not captured in the previous version, revealing additional layers of color and depth. NGC 3370 is part of a small group of neighboring galaxies that also includes NGC 3447 and NGC 3455—all of which have been studied by Hubble's powerful eye on the cosmos.
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