February 4, 2024

By Nick Strobel | 02/04/24
Earth February at 8:30 PM looking south

February 4, 2024

The spring schedule of evening shows at the William M Thomas Planetarium will begin on February 15 with “Supervolcanoes” about the largest volcanic eruptions that can cause mass extinctions. The spring schedule will include our two Mars future missions shows “Mars 1001” and “Destination Mars” in March and “Black Holes” in early April. If the finance processing can get worked out, the spring lineup will include a new show about future moon bases in mid-April. See the Planetarium’s website at bakersfieldcollege.edu/community/planetarium for more details about the shows.

Our evening planet lineup now includes only Jupiter as Saturn fades in the evening twilight. Jupiter will be the first star-like thing you see after the sun sets. It will be high in the south below Aries and close to the head of Cetus (at the east end of Cetus).

Last February, I described the magnitude system astronomers use to specify how bright something appears. I noted how it is a non-linear scale like the Richter scale we use for earthquakes but the magnitude system uses powers of 2.5. I also noted that the scale is a bit backwards. When it was invented many centuries ago, the very bright stars were first class (magnitude 1) stars while the dimmest visible to the eye were sixth class (magnitude 6) stars. Magnitude 6 stars appear to be about 100 times dimmer than a magnitude 1 star. Later when we invented photometers that could accurately measure brightnesses, we found that the eye is a logarithmic detector and we set the scale so that the magnitude 6 star is exactly 100X dimmer than a magnitude 1 star. That scaling means we work with powers 2.5 (the fifth root of 100).

Objects that are really bright have magnitudes that are less than zero, i.e., negative magnitudes. Jupiter reflects so much sunlight that is currently at magnitude –2.34. The brightest true star in the night sky is Sirius at the nose of Canis Major with a magnitude –1.47 which means Sirius is indeed bright but not quite as bright as Jupiter. Working with the powers of 2.5, it means that Jupiter is slightly more than twice as bright as Sirius.

The two brightest stars in Orion, blue-white Rigel at the lower right corner has magnitude 0.15 and red Betelgeuse at the upper left corner has magnitude 0.43. That means they are bright stars visible even from the center of Bakersfield but they are much dimmer than Jupiter. Jupiter is almost ten times brighter than Rigel and it is almost 13 times brighter than Betelgeuse. The  bright star, Procyon at the back end of Canis Minor has a magnitude 0.37, so its brightness is in between Rigel and Betelgeuse.

Capella, at one vertex of the pentagon of Auriga, is a very bright 0.06 magnitude, making it one-ninth as bright as Jupiter. The two bright stars at the heads of the Gemini twins, Pollux and Castor, have magnitudes of 1.14 and 1.56, respectively. By the way, one way to remember which of the two is Castor and the other is Pollux, is that Castor is closer to Capella and both begin with the letter “C” while Pollux is closer to Procyon and both of them begin with the letter “P”.

By 8:30 p.m., we’ll see Leo above the horizon with Regulus (magnitude 1.30) at the end of the Sickle (backward question mark) and Denebola (magnitude 2.12) at the far left (east) end of Leo. Today is the midpoint between the December solstice, marking the beginning of winter, and the March equinox that marks the beginning of spring, so in our evening sky we see the brilliant winter constellation Orion high up in the south as the spring constellation Leo makes its appearance in the east.

Tonight the moon is a waning crescent, just 30% illuminated and its magnitude is –11.28. It rises with the stars of Scorpius at about 3:50 a.m. The “morning star” Venus will appear at about 5:30 a.m. — about an hour before sunrise. Brighter than Jupiter, Venus shines at –3.95 magnitude. A super-thin crescent moon will be near Venus the morning of February 7. You might be able to spot Mars to the lower left of Venus. Venus, Mars, and the moon will form an equilateral triangle with Venus the top middle point, Mars the lower left point, and the moon at lower right.

The flying days for the Mars Ingenuity helicopter ended last week after an extremely successful operation that lasted 60-some flights and over two years more than its original mission. Because of Ingenuity’s success, all future rover missions will include a helicopter (or two) as part of the operation.

Hopefully, tomorrow night will see the launch of NASA’s Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission. PACE will help us better understand how the ocean and atmosphere exchange carbon dioxide, measure key atmospheric variables associated with air quality and Earth's climate, and monitor ocean health, in part by studying phytoplankton, tiny plants, and algae that sustain the marine food web. Although, the James Webb Space Telescope and the Hubble Space Telescope get more press coverage, NASA actually has more science satellites looking down at Earth to gives us a global perspective on Earth’s dynamic systems that sustain life.

Nick Strobel

Director of the William M Thomas Planetarium at Bakersfield College

Author of the award-winning website www.astronomynotes.com