A Distant Supernova Discovery
This latest image from the Hubble Space Telescope features a distant galaxy located about 600 million light-years away in the constellation Gemini. This galaxy recently hosted a supernova, named SN 2022aajn, which was discovered in November 2022. In the image, the supernova appears as a bright blue dot at the center, standing out against the galaxy’s hazy glow.
Why Observe This Supernova?
Since its discovery, SN 2022aajn has not been widely studied. So why did Hubble turn its attention to it? This supernova is classified as a Type Ia, a special kind of stellar explosion that occurs when the core of a dead star reignites and detonates.
Type Ia supernovae are valuable to astronomers because they serve as reliable cosmic yardsticks. They are believed to have a consistent intrinsic brightness, meaning they all emit the same amount of light regardless of their location in the universe. By comparing how bright the supernova appears from Earth to its known true brightness, scientists can determine its distance and, in turn, measure the distance to its host galaxy with remarkable accuracy.
Measuring Cosmic Distances with Supernovae
This seemingly simple measurement method is complicated by cosmic dust. The farther away a supernova is, the fainter and redder it will appear — but intergalactic dust can make a supernova appear fainter and redder as well. To understand this complication, researchers will use Hubble to survey a total of 100 Type Ia supernovae in seven wavelength bands from the ultraviolet to the near-infrared.
This image combines data taken at four infrared wavelengths. Infrared light passes through dust more easily than visible or ultraviolet light. By comparing the brightness of the sampled supernovae across different wavelengths, researchers can disentangle the effects of dust and distance, helping to improve measurements of galaxies billions of light-years away and even the expansion of our Universe.
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.