Sky & Telescope Errata 2023

The editors of Sky & Telescope make every effort to provide accurate information, but errors do sometimes slip through. We correct all mistakes online as well as printing corrections in the magazine. So if you see something questionable in the magazine, check below to see if it's a known problem.

This article lists all known errors in issues of Sky & Telescope for 2023. See also the errata listings for other years.

January 2023

Page 58: In “What Makes a Good Planetary Telescope,” the amount of light in the Airy disk of a telescope with a 33% central obstruction is not 68%, with 32% going into the diffraction rings. The correct percentage is 65% of light concentrated in the Airy disk, with the remaining 35% going into the diffraction rings.

February 2023

Page 48: In “Comet Prospects for 2023,” 1.9 astronomical units is equal to 280 million kilometers and 180 million miles.

March 2023

Page 34: “Earth’s Wellspring” misstated hydrogen’s makeup: A hydrogen atom has one proton and one electron.

Page 72: In “What Is Opposition?,” the interior planets achieve eastern elongation as they catch up with us in our orbit, and western elongation occurs after each has passed us by.

April 2023

Page 41: In April’s Sky at a Glance, the new Moon occurred at 4:13 UT on April 20th.

May 2023

Page 26: Although Ulugh Beg’s star catalog was a significant improvement on Ptolemy’s, its average accuracy was nowhere near as good as that of Tycho Brahe’s star catalog, unlike what was stated in “The Past and Future of Star Names.”

Page 31: In “The Past and Future of Star Names,” the name Achernar comes from akhir al-nahr (River’s End).

June 2023

Cover: The cover image perpetuates a common misunderstanding. The tree on the June cover is probably a small ponderosa pine, not a bristlecone pine.

Page 45: In “Visiting Ophiuchus,” Aesculapius carries a rod with a single snake wrapped around it, known as the Staff of Aesculapius. The “caduceus” is a staff entwined with two snakes belonging to Hermes, the Greek messenger god. Both staffs serve as a symbol for the medical profession today.

August 2023

Page 27: Williamina Fleming discovered Z Centauri in December 1895 on a photographic plate taken in July of that year.

September 2023

Page 74: In “What Is a Spectrum?,” the base of a candle flame isn’t bluer because it’s hotter. While the orange part of candle flames can indeed be treated as blackbody emitters, the blue base of a flame comes from chemical reactions that emit light at specific wavelengths and is thus not a blackbody.

October 2023

Page 49: The first-quarter Moon sets shortly before midnight on October 22nd and won't disturb our view of the Orionids at their best between 2 a.m. and dawn.

Page 74: In “What Is an Aurora?,” we wrote that Mercury is the only planet without aurorae. A day after we went to press, a new research paper brought to our attention that this is not a straightforward matter. Particles accelerated within Mercury’s magnetosphere do indeed travel down field lines and interact with the planet in a way that reflects the magnetosphere’s structure. However, the particles interact with the surface, not an atmosphere, creating X-ray fluorescence instead of exciting or ionizing atoms. Thus, while different, the phenomenon is closely analogous to terrestrial aurorae and can be called an “aurora” for simplicity’s sake.