My first Magazine Sky & Telescope - 04.2019

FROM OUR READERS This is what hap- pens if Joe doesn’t get out of bed fast enough when I want my cat food: I torture him by ripping up his Sky & Telescope until he gives in. “Betsy” Bauman Salt Lake City, Utah t You have to get up pretty early in the morning to keep Betsy from devouring the latest issue of S&T. 6 Celestial Celebration Catch a Speeding Star Thank you for publishing Scott Levine’s “New Year’s Eve Celestial Celebration” (S&T: Dec. 2018, p. 22). Although I’m a longtime subscriber, I’ve spent little time observing the sky in my severely light-polluted urban backyard. Before reading this article, I was ignorant of the Summer Triangle, Winter Hexagon, and the names and distances of the brightest stars in the sky. But motivated to identify the brightest stars visible on New Year’s Eve and New Year’s Day morning, I woke up early in November and December to familiarize myself with the Winter Hexagon in the west- ern sky and spent time spotting Vega, Altair, and Deneb just after sunset. When the night of December 31 ﬁ nally arrived, I was prepared and managed to spot all the stars on the list. There are probably many others who, like me, love the evening sky in principle but are limited by circum- stance or willpower to actually engage in observation. Articles like this give beginners an interesting objective to shoot for, and I’m grateful for the inspiration to begin serious observation at the age of 43. Ken Croswell’s fascinating article “The Fastest Stars Escaping the Galaxy”(S&T: Dec. 2018, p. 30) makes me wonder: Have we spied such stars that have actu- ally “escaped” and are wandering about extragalactically? For that matter, do we know of any stars, or have any candi- dates, from another galaxy that have been captured by ours (analogous to the interstellar comet or asteroid we now call ‘Oumuamua)? Patrick Doherty San Francisco, California Ralph Fusco Edison, New Jersey A PR I L 2 019 • SK Y & TELESCOPE Joel Marks Milford, Connecticut When I was in high school I envisioned stars wandering aimlessly among the galaxies, and I even coined a term for them: maverick stars. In 1982 I wrote to Dr. Carl Sagan asking, “Are there stars not belonging to any galaxy just drifting aimlessly through intergalactic space?” He was kind enough to respond but kept his answer very short: “Probably.” We’ve come a long way since 1982. But it was not until 2005 that the ﬁ rst “maverick” star was observed: a hyper- velocity star. I had envisioned them more than 40 years ago; I just didn’t realize how fast they’d be moving. Meet the Thuloids The solar system contains planets, dwarf planets, and minor planets, all of which can possess moons. Minor planets within Jupiter’s orbit are labeled asteroids, and these may be further subdivided into families according to their orbital or chemical characteristics. Orbiting the Sun in a 1:1 resonance with one of the major planets we have the Trojans, and between the orbits of Jupiter and Neptune there are a few Centaurs. The latter two groups derive their names from Greek mythology. In clas- sical times the Greeks had a name for a far-off, icy-cold, practically inac- cessible place, namely Thule; a town in northern Greenland once had this name. In the solar system there is also a region that is distant, extremely cold, and difﬁ cult to reach: the space outside the orbit of Neptune, populated with many minor planets. I propose to name these thuloids after Thule, giving them a short yet classical name. One would no longer have to refer to them as trans- Neptunian objects (which is too long) or TNOs (which is an acronym). The thuloids in the Kuiper Belt also contain families, one of which is the plutoids. The group of icy objects making up the scattered disk is as yet unnamed (not counting “scattered disk objects”), but scythoids comes to mind, after the Scythians, a martial people with whom the Greeks had a trouble- some relationship. Holger Nielsen Støvring, Denmark A Fount of Information I recently celebrated my 60th year as an amateur astronomer. During my early formative years, issues of Sky & Telescope and the RASC Observer’s Handbook were my reliable reference sources, coupled with periodic visits to the Fels Planetar- ium in my hometown of Philadelphia. Over the past decade or so, I’ve been concerned about S&T’s seeming inability to publish issues with real amateur impact from cover to cover. Your December 2018 issue arrested that trend in spades. I maintain a monthly Hunger for Knowledge

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