Sky and Telescope - April 2015 - 8

Letters

The news brief "First Direct Exoplanet
Spin Measurement" (S&T: Sept. 2014, p.
18) gives the impression that the rotation of
Beta Pictoris b bolsters the hypothesis that
the more massive a planet is, the faster it
rotates. Beta Pic b's surface, or cloud tops in
this case, might move at a faster clip than
Jupiter's (25 km/s vs. 13 km/s), but that
doesn't mean Beta Pic b rotates faster than
Jupiter, or even than Earth; for that determination we need to know the exoplanet's
size. Beta Pic b has 11 times Jupiter's mass,
but do we know its size at all?
Jim Baughman
West Hollywood, California
Editor's Note: Beta Pic b isn't a transiting planet, so we can't easily determine its
radius. However, with some calculations
based on direct imaging, the astronomers
estimated that the exoplanet is 1.65 times the
size of Jupiter. This implies that the length of
day is only 8 hours, whereas Jupiter's day is
10 hours, supporting the team's argument.

Bring Back the Fun
Bert Probst made some good points about
introducing people to astronomy in his
Focal Point "Winning Converts to the
Cause" (S&T: Oct. 2014, p. 86). My suggestion is, if you know someone who is not
interested in the science of astronomy,
you might want to introduce him or her
to astronomizing, a word I like to use to
describe the aesthetic side of skygazing
- in other words, a recreation similar
to earthly sightseeing. This is especially
enjoyable when something is changing
right before your eyes, such as the mountain shadows on the crescent Moon. I can

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8

April 2015 sky & telescope

S&T: LEAH TISCIONE

Spin: How Sure Are We?

watch that again and again. And then there
are occultations. My favorite was the occultation of a star by Saturn and its rings.
Years ago I acquired a used Celestron
5-inch Schmidt-Cassegrain. It came with
all the accessories, but I don't use the
tripod or the electric drive. Instead, I just
place it on a picnic table with its equatorial
wedge and enjoy the show through the
eyepiece. I don't do occultation timings
or any other measurements: I just like to
watch. I'm a retired physics professor, but
I prefer to separate the science of astronomy from the fun of astronomy. All of the
new gadgets are great for serious astronomers, but I think they can be imposing
to beginners and perhaps turn them oﬀ
to astronomy. Maybe we should get back
to basics, downplay all those gadgets, and
focus on showing people the fun of the
hobby instead.
William DeBuvitz
Mendham, New Jersey
As a retired science educator, I have grave
concerns about both what is being taught
in schools today and how it's being taught.
The frustration I have is that there seems
to be no regard for age-appropriateness.
Scientiﬁc ideas and concepts appropriate for older students are creeping into
requirements for younger students, making it harder for them to learn.
Once while teaching my students
about solids, liquids, and gases, I used the
standard model: to show a gas, I drew dots

far apart on the board. I looked at my students and saw blank faces. I asked, "What
do you think is between these particles?"
Hands went up quickly. "Air" was the
answer.
"How many agree?" I asked.
Almost all agreed.
Things aren't always as simple as we
think they are.
There needs to be a change in our
culture to help make science as fun and
interesting as it should be. The American Association for the Advancement of
Science and the National Science Teachers Association have together created a
two-volume Atlas of Science Literacy (www.
project2061.org/publications/atlas), which
lays out the learning benchmarks K-12
students can successfully hit in order to
build up their understanding of a particular topic, from the solar system to how
scientiﬁc inquiry works. These are the
best guidelines for what is appropriate at
each age level, and I recommend them to
anyone writing science curricula. Maybe
S&T could also have age-appropriate ideas
or activities as part of the magazine.
Herb Hoyack
Mechanicsville, Maryland

Daytime Observing
I enjoyed Chris Dalla Piazza's article
"Stars & Planets in Broad Daylight" (S&T:
Oct. 2014, p. 36). For many years I've also
observed during the day. I use an 8-inch
Celestron with standard setting circles
and a permanent mount that's polar
aligned. I normally set up the telescope
between 11 a.m. and 4 p.m., so that the
Sun is well above the horizon before I start
the hunt. So far I've seen 62 stars, four of
them double, along with the planets Mercury, Venus, Mars, Jupiter, and Saturn.
The fainter, 5.1-magnitude member of the
double Albireo is the faintest star that I've
seen during the day so far.
Both Albireo (magnitudes 3.1 and 5.1)
and the double Lambda Ori (magnitudes
3.6 and 5.5) required a very clear blue sky to
separate the pairs. In terms of planets, Mercury and Venus are perfect to look at when
http://www.project2061.org/publications/atlas http://www.project2061.org/publications/atlas
Sky and Telescope - April 2015

Table of Contents for the Digital Edition of Sky and Telescope - April 2015
