APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Perihelion Sun 2023
Explanation: Perihelion for 2023 , Earth's closest approach to the Sun, was on January 4 at 16:17 UTC. That was less than 24 hours after this sharp image of the Sun's disk was recorded with telescope and H-alpha filter from Sydney, Australia, planet Earth. An H-alpha filter transmits a characteristic red light from hydrogen atoms. In views of the Sun it emphasizes the Sun's chromosphere, a region just above the solar photosphere or normally visible solar surface. In this H-alpha image of the increasingly active Sun planet-sized sunspot regions are dominated by bright splotches called plages. Dark filaments of plasma snaking across the solar disk transition to bright prominences when seen above the solar limb .
| Date | January 14, 2023 |
|---|---|
| Credit | Image Credit & Copyright: Peter Ward ( Barden Ridge Observatory ) |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |


