UDFORSKBIBLIOTEK
searchclose
shopping_cart_outlined
exit_to_app
category_outlined / Videnskab
SKY & TELESCOPESKY & TELESCOPE

SKY & TELESCOPE

December 2019

Since the first issue was published in 1941, Sky & Telescope has become the go-to resource for all things star and space. This magazine is considered the complete resource for the astronomy enthusiast. Offering everything from product reviews, buyer's recommendations, and current events news to tips, how-to articles, and computer software, fascinated readers will find a wealth of information and suggestions on how to hone their hobby. Devoted amateurs, professionals, and academics would all find a subscription to Sky & Telescope magazine of interest.

Land:
United States
Sprog:
English
Udgiver:
F+W Media, Inc. - Magazines
Læs merekeyboard_arrow_down

I DENNE UDGAVE

access_time2 min.
time travel

TO AN ASTRONOMER INTENT ON measuring change, 100 years might as well be no time at all. Professionals and amateurs alike are used to evaluating variations that occur over millions or even billions of years. What’s a century in the lifetime of a star or the parallax shift of a distant galaxy? Yet when it comes to the field of astronomy, a century has brought truly radical change, as Klaus Brasch chronicles in his article on page 58. You might liken the transformation to a blue supergiant before and after going supernova. To get my own sense of this — Brasch considers other examples — I looked at two books, one published in 1904 and the other in 2004. (I chose those years because my paternal grandfather was born in the first…

access_time1 min.
sky & telescope

Founded in 1941 by Charles A. Federer, Jr. and Helen Spence Federer EDITORIAL Editor in Chief Peter Tyson Senior Editors J. Kelly Beatty, Alan M. MacRobert Science Editor Camille M. Carlisle News Editor Monica Young Associate Editors S. N. Johnson-Roehr, Sean Walker Observing Editor Diana Hannikainen Senior Contributing Editors Dennis di Cicco, Robert Naeye, Roger W. Sinnott Contributing Editors Howard Banich, Jim Bell, Trudy Bell, John E. Bortle, Greg Bryant, Thomas A. Dobbins, Alan Dyer, Tom Field, Tony Flanders, Ted Forte, Sue French, Steve Gottlieb, David Grinspoon, Shannon Hall, Ken Hewitt-White, Johnny Horne, Bob King, Emily Lakdawalla, Rod Mollise, James Mullaney, Donald W. Olson, Jerry Oltion, Joe Rao, Dean Regas, Fred Schaaf, Govert Schilling, William Sheehan, Mike Simmons, Mathew Wedel, Alan Whitman, Charles A. Wood Contributing Photographers P. K. Chen, Akira Fujii, Robert Gendler, Babak Tafreshi ART & DESIGN Art Director Terri…

access_time6 min.
from our readers

Membership Has Its Privileges Early this year a fellow member of the Smoky Mountain Astronomy Society (SMAS) and I rode to the top of Chilhowee Mountain in eastern Tennessee to take pictures of the elusive Omega Centauri. The summit overlooks Great Smoky Mountains National Park and has a very good view of the southern sky. Unfortunately, clouds lingered there for the whole night, and we had to pick another target. The Hercules cluster, M13, was rising in the east and in perfect position for photography. Three hours and 20 minutes later, I had accumulated a hundred 2-minute exposures, and Jammey Church processed them. We created a beautiful picture with brilliant colors, but the story doesn’t end there. We proudly showed the results to other SMAS members, with one taking an acute interest. Michael…

access_time2 min.
75, 50 & 25 years ago

December 1944 Galaxy Centers Resolved “One of the observational problems that most astronomers expected could be solved only with the new 200-inch telescope has been successfully tackled with the Mount Wilson 100-inch by Dr. [Walter] Baade. Making long exposures on red-sensitive photographic plates, he has [resolved] into stars the nebulous nucleus of the Andromeda galaxy and its two companions, Messier 32 and NGC 205. The Griffith Observer attributes this success to the Los Angeles–Pasadena dimout, which allowed longer exposure times than were previously possible.” The term “dimout” refers to the nighttime use of blackout curtains in homes and restrictions on outdoor lighting during World War II. December 1969 Messier’s Mistake “It can be simply demonstrated that the lost Messier object M91 is very probably the galaxy NGC 4548… M91 was the last of a…

access_time10 min.
news notes

STARS A Century of Amateur Observations Sheds Light on Stellar Evolution THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS (AAVSO) has been monitoring the star T Ursae Minoris (T UMi) since its brightness variations were discovered in 1912. Now, astronomers are using this century of observations to understand the star’s recent change in behavior. For the first few decades, the star’s brightness went up and down by about 4½ to 5 magnitudes over the course of some 300 days. But over the past 20 years, this pattern changed to a more rapid cycle: The star now brightens and fades by only 1½ to 2 magnitudes over a period of roughly 200 days. Astronomers noting this change have proposed that the star is undergoing a rare and (from a stellar perspective) short-lived change in structure. Now,…

access_time2 min.
in brief

India’s Lander Crashes on the Moon India’s attempt to land on the Moon ended when mission control lost contact with the Vikram lander, part of the Chandrayaan 2 mission, moments before touchdown. It was a disappointing finish to a six-week journey. After launch, a series of orbital boosts gradually raised the mission’s elliptical orbit around Earth, until it was captured by the Moon’s gravity on August 20th. Vikram separated from the orbiter on September 2nd for a fourday descent that took it 100 kilometers (62 miles) down to the lunar surface. Contact was lost at just 2 km above the surface; the lander appears to have landed in one piece but efforts to restore communication have failed. Vikram landed near its target, on a plain near the lunar south pole. It…

help