Andromeda Island Universe

The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy some two and a half million light-years away. But without a telescope, even this immense spiral galaxy – spanning over 200,000 light years – appears as a faint, nebulous cloud in the constellation Andromeda. In contrast, a bright yellow nucleus, dark winding dust lanes, expansive blue spiral arms and star clusters are recorded in this stunning telescopic image. While even casual skygazers are now inspired by the knowledge that there are many distant galaxies like M31, astronomers debated this fundamental concept 100 years ago. Were these “spiral nebulae” simply outlying components of our own Milky Way Galaxy or were they instead “island universes”, distant systems of stars comparable to the Milky Way itself? This question was central to the famous Shapley-Curtis debate of 1920, which was later resolved by observations of M31 in favor of Andromeda, island universe. via NASA

Wikipedia article of the day for April 30, 2020

Wikipedia article of the day is Isopogon anemonifolius. Check it out: Summary: Isopogon anemonifolius is a shrub of the family Proteaceae which is native to eastern New South Wales in Australia. It occurs naturally in woodland, open forest, and heathland on sandstone soils. Described in 1796 by Richard Salisbury, I.Β anemonifolius usually ranges between 1 and 1.5 metres (3Β 1⁄4 and 5 feet) in height, generally being smaller in exposed heathland. Its leaves are divided and narrow, though broader than those of the related Isopogon anethifolius, and have a purplish tinge during the cooler months. The yellow flowers appear during late spring or early summer and are displayed prominently. They are followed by round grey cones, which give the plant its common name drumsticks. The small hairy seeds are found in the old flower parts. A long-lived plant (up to 60Β years), I.Β anemonifolius resprouts from its woody base after bushfire. It grows readily in the garden if located in a sunny or partly shaded spot with sandy soil and good drainage.