Bakersfield Night Sky — May 2, 2026
We’re now heading into the last regular week of the spring semester at Bakersfield College before Finals week. After Finals week, the William M Thomas Planetarium is closed for the summer.
Yesterday, May 1, the moon was at full moon phase. Since the lunar phase cycle is 29.5 days long, May will have a “blue (full) moon” at the end of the month, according to one definition for a blue moon. The moon is now in the waning gibbous part of the cycle where we still see more than half of the lit side of the moon but the amount of light decreases. The moon will be at last (or third) quarter on May 9 and then be a waning crescent for the next week with the crescent sliver getting ever thinner until the new phase on May 16, that marks the beginning of the lunar phase cycle. In the early pre-dawn morning of May 14, you’ll see the waning crescent moon rising with Mars trailing shortly behind it in the east-northeast.
In our evening sky, the spring constellations are on full display. Leo is high in the south by 9 p.m. It has the distinctive sickle shape for the lion’s head and chest but for all the city-folk who attend the planetarium shows, I call it the “backward question mark”. The bright star, white-hot Regulus, is at the bottom of the sickle/question mark where the lion’s chest would be.
You can find the sickle by looking for it high in the south in a spring evening or do what I show the planetarium audiences: locate the Big Dipper (part of Ursa Major) which is always in the north and plenty bright enough to see even with the city lights and instead of using the two pointer stars at the end of the bowl part of the asterism to point “upward” above the bowl to the North Star (Polaris), extend the line of the two pointer stars “downward” (south) until you run into the Sickle asterism. Although the alignment is not as good as the one for locating Polaris, it works well enough. That technique works wherever Leo is in the sky. In late winter, we see Leo rising in the east in the evening. In late summer, Leo is in the west in the evening.
You can use the curve or arc of the handle of the Big Dipper to find Arcturus, the second brightest star visible to us in Kern County. Extend the arc to the first bright star you come to (“arc to Arcturus”). Only Sirius in Canis Major, which is low in the southwest in spring evenings, is a brighter star. The two really bright “stars” you see in the west in the evening are the planets Venus (lower of the two) and Jupiter (higher up in Gemini, above Orion). Planets shine from reflected sunlight off of their clouds while stars are hot enough to produce their own visible light.
Venus and Jupiter will also usually have a steady glow instead of a twinkle like the stars do. Venus and Jupiter are close enough to us that they have an easily seen disk, so despite the turbulent movement of the air, their light still appears to be coming from the same direction. Stars are so far away that they appear as point sources and air turbulence will refract/bend their light all about. Without a telescope, the turbulence makes the stars twinkle. Under high magnification, we see that the point source star is broken up into many multiple images that dance about wildly in a hopeless mess. Well, not “hopeless”. There are ways to reduce or eliminate the atmospheric distortion: you can put the telescope in space (expensive!), you can use adaptive optics (cheaper) to compensate for turbulence in real time, or you can take a bunch of fraction-of-a-second exposures to freeze the dancing motion and shift-and-stack the best short exposures (cheapest but not real time).
Two astronomy research results about the first stars made in the universe were announced recently. The first used the James Webb Space Telescope to find stars that probably formed from pristine gas clouds made of only hydrogen and helium without any of the heavier elements (such as carbon and oxygen) made by earlier stars and blasted outward in their explosive deaths to “pollute” the surrounding gas clouds. Finding these first stars is one of the key goals of Webb and the object called “Hebe” (“Helium Balmer Emitter”) lies near an extremely distant proto-galaxy catalogued as GN-z11 whose light is coming from just 400 million years after the Big Bang (i.e., traveling to us for the past 13.4 billion years). Although the evidence is strong for this detection of the first stars, there have been other claims of finding the first stars that haven’t held up to testing of the claims by others.
The second story involves looking at the oldest stars in our home galaxy, the Milky Way, to set limits on the possible age of the universe. The usual method of determining the age of the universe uses the expansion rate of the universe to then “run the expansion backward” to find when everything was all at one spot. Different methods for measuring the expansion rate have disagreed leading to an uncertainty in the age estimates of the universe of about 1 billion years around the current best value of 13.8 billion years. A team of astronomers used a sample of 160 very old stars from the third data release of the Gaia mission that have well-determined ages. The statistical peak of the distribution of age measurements for these stars is 13.6 billion years with an uncertainty range of 1 billion years. If it takes about 200 million years to form the first stars, then the universe must be at least 13.8 billion years old. Future data releases from the Gaia mission will lead to larger sample sizes that can shrink the uncertainty but this totally different technique gives an age of the universe in agreement with the expansion rate method.
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Director of the William M Thomas Planetarium at Bakersfield College
Author of the award-winning website www.astronomynotes.com
