ask-astro-web-extra-why-is-the-fourth-known-planet-in-an-extrasolar-system-labeled-with-an-e-shouldnt-that-be-the-fifth-known-planet-or-is-the-star-always-ahttps://www.astronomy.com/science/ask-astro-web-extra-why-is-the-fourth-known-planet-in-an-extrasolar-system-labeled-with-an-e-shouldnt-that-be-the-fifth-known-planet-or-is-the-star-always-a/Ask Astro web extra: Why is the fourth known planet in an extrasolar system labeled with an "e"? Shouldn't that be the fifth known planet? Or is the star always "a"? | Astronomy.comcategories:Science | tags:Ask Astro, MagazineInStockUSD1.001.00sciencearticleASY2023-05-182010-01-2546529
Ask Astro web extra: Why is the fourth known planet in an extrasolar system labeled with an “e”? Shouldn’t that be the fifth known planet? Or is the star always “a”?