Astronomy Picture Of the Day (APOD)RCW 86: Historical Supernova Remnant
In 185 AD, Chinese astronomers recorded the appearance of a new star in the Nanmen asterism. That part of the sky is identified with Alpha and Beta Centauri on modern star charts. The new star was visible to the naked-eye for months, and is now thought to be the earliest recorded supernova.
Unraveling NGC 3169
Spiral galaxy NGC 3169 looks to be unraveling like a ball of cosmic yarn. It lies some 70 million light-years away, south of bright star Regulus toward the faint constellation Sextans. Wound up spiral arms are pulled out into sweeping tidal tails as NGC 3169 (left) and neighboring NGC 3166 interact gravitationally.
APOD: 2023 March 1 Б The Flaming Star Nebula
Is star AE Aurigae on fire? No. Even though AE Aurigae is named the Flaming Star and the surrounding nebula IC 405 is named the Flaming Star Nebula, and even though the nebula appears to some like a swirling flame, there is no fire.
APOD: 2023 February 28 Б Crescent Moon Beyond Greek Temple
Why is a thin crescent moon never seen far from a horizon? Because the only geometry that gives a thin crescent lunar phase occurs when the Moon appears close to the Sun in the sky.
APOD: 2023 February 27 Б Zodiacal Ray with Venus and Jupiter
What's causing that unusual ray of light extending from the horizon? Dust orbiting the Sun. At certain times of the year, a band of sun-reflecting dust from the inner Solar System appears prominently after sunset or before sunrise and is called zodiacal light.
APOD: 2023 February 26 Б Saturns Iapetus: Moon with a Strange Surface
What would make a moon look like a walnut? A strange ridge that circles Saturn's moon Iapetus's equator, visible near the bottom of the featured image, makes it appear similar to a popular edible nut.
Crescent Moon Occultation
On February 22, a young Moon shared the western sky at sunset with bright planets Venus and Jupiter along the ecliptic plane. The beautiful celestial conjunction was visible around planet Earth. But from some locations Jupiter hid for a while, occulted by the crescent lunar disk.
Jones Emberson 1
Planetary nebula Jones-Emberson 1 is the death shroud of a dying Sun-like star. It lies some 1,600 light-years from Earth toward the sharp-eyed constellation Lynx. About 4 light-years across, the expanding remnant...
APOD: 2023 February 23 Arp 78: Peculiar Galaxy in Aries
Peculiar spiral galaxy Arp 78 is found within the boundaries of the head strong constellation Aries. Some 100 million light-years beyond the stars and nebulae of our Milky Way galaxy, the island universe is an enormous 200,000 light-years across.
APOD: 2023 February 22 Б Our Increasingly Active Sun
Our Sun is becoming a busy place. Only two years ago, the Sun was emerging from a solar minimum so quiet that months would go by without even a single sunspot. In contrast, already...