January 28, 2023
Why Does the Star Sirius Flicker?
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The Marvel of Sirius: Unveiling the Dog Star
Sirius, often called the Dog Star, is the brightest star visible from Earth and is part of the constellation Canis Major. It has an apparent magnitude of -1.46, making it nearly twice as bright as the next brightest star, Canopus. This stellar system is located about 8.6 light-years away from Earth, making it one of our closest stellar neighbors (StarFacts) (The Planets).
Why Does Sirius Twinkle?
The twinkling of Sirius, like other stars, is due to atmospheric distortion. As the light from Sirius passes through Earth's atmosphere, it is refracted by different air layers with varying temperatures and densities. This effect is more noticeable for Sirius because of its brightness and when it is observed low on the horizon, where the atmospheric distortion is greatest.
Interesting Facts About Sirius
- Binary Star System: Sirius is a binary star system consisting of Sirius A, a bright main-sequence star, and Sirius B, a faint white dwarf. Sirius A is about 25 times more luminous than the Sun and twice as massive, while Sirius B, though much smaller and dimmer, is hotter than Sirius A.
- Cultural and Historical Significance: Sirius has been significant in various cultures throughout history. The ancient Egyptians associated it with the goddess Isis and used its heliacal rising to predict the annual flooding of the Nile. The Greeks and Romans linked its appearance to the hottest days of summer, known as the "dog days." In Polynesian navigation, Sirius played a crucial role due to its brightness and position in the sky.
- Physical Characteristics: Sirius A has a surface temperature of approximately 10,000°C and is 1.71 times the diameter of the Sun. Sirius B, the companion star, is a white dwarf and the first of its kind to be discovered, with a mass comparable to the Sun but a size similar to Earth.
- Observational Highlights: Sirius can sometimes be seen during the day if the observer is at a high altitude and the Sun is low on the horizon. The system's brightness is expected to increase over the next 60,000 years as it moves closer to our solar system, before gradually dimming as it moves away.
For a deeper dive into the details about Sirius and its significance, check out Sky & Telescope and The Planets.
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By Dennis Mammana Week of March 8-14, 2026 If you hear the word "superstar," what immediately comes to mind? Perhaps names like Tom Hanks, Taylor Swift or LeBron James? That's certainly understandable; they are all undisputed superstars who attract the attention of paparazzi and fans alike. If you're an astronomer, however, you may answer this question differently. For example, when I hear the word "superstar," I think of UY Scuti, WOH G64 or RSGC1-F01. Yes, these are superstars, but not quite how people may think. These are some of the largest stars known in our galaxy and, for that reason, are quite intriguing to us celestial paparazzi. Regular readers of this column know that our sun is also a star. It appears big and bright in our daytime sky because not only is it rather close (about 93 million miles away), it's also pretty large (nearly a million miles across). It sounds huge, but our star is rather small on a cosmic scale, and believe it or not, there are stars out there that would dwarf our sun and make it look tiny. These are the true superstars! Until recently, the largest star known was given the hopelessly poetic name of UY Scuti. At a distance of some 9,500 lightyears from Earth, UY Scuti is what is known as a red hypergiant star, with a diameter some 1,700 times that of the sun! All that changed recently, however, when astronomers found a gargantuan star some 2,150 times larger than our sun! It's named Stephenson 2-18, and if you'd like to get a peek at this stellar behemoth, you'll need more than your eyes. At a distance of some 18,900 lightyears, it appears 5,100 times fainter than we can see without a telescope. If you have no telescope but would still like to see a celestial superstar, you're in luck. There's one shining in our night sky right now; it's one of the brightest up there and is named Betelgeuse. Betelgeuse sparkles brightly in the northeastern corner of Orion, the hunter, and you can see its orange light midway up in the southern sky after dark this week. With about 15-20 times more mass than our sun, Betelgeuse is known as a red supergiant star for good reason. While we could align 109 Earths across the face of our sun, we would need at least 700 suns to cross the face of Betelgeuse! Indeed, this star is so immense that if it replaced our sun at the center of our planetary system, Betelgeuse would engulf the orbits of Mercury, Venus, Earth and Mars, and stretch part of the way to Jupiter! Yet it appears as a simple point of light in our night sky because of its tremendous distance from us — some 3,100 trillion miles, or about 520 lightyears. Betelgeuse is easily one of the largest known stars, though its size fluctuates by as much as 60% as the star shudders and pulsates on its way to an eventual supernova explosion, thousands or millions of years from now. Or tonight. We just don't know. I hope you'll step out under the night sky soon to meet this remarkable superstar for yourself! Visit Dennis Mammana at dennismammana.com. To read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com. Learn More About Borrego Springs
Borrego Springs, CA The Anza-Borrego Desert Natural History Association (ABDNHA) will host the 2026 Borrego Home & Garden Tour on Saturday, March 14, 2026, from 9:00 a.m. to 3:00 p.m. The public is invited to explore four private homes and gardens at their own pace in Borrego Springs. This annual tour is a fundraiser benefiting ABDNHA, the educational 501(c)(3) nonprofit that supports interpretation, education, and stewardship connected to the Anza-Borrego Desert region. Event details Event: 2026 Borrego Home & Garden Tour Date: Saturday, March 14, 2026 Time: 9:00 a.m. to 3:00 p.m. Format: Self-guided tour of four private homes and gardens Tickets $30 General Public $24 ABDNHA Members $20 ABDNHA Volunteers Early purchase discount: Buy by March 8 and save $2 per ticket . How to purchase Tickets are available online at abdnha.org/gardentour and in person at the ABDNHA Desert Nature Center , 652 Palm Canyon Drive, Borrego Springs . Questions: (760) 767-3098 Important guidelines Tickets are non-refundable . For guest safety and property rules, no strollers or dogs are permitted. About ABDNHA The Anza-Borrego Desert Natural History Association (ABDNHA) is a nonprofit organization that supports education and interpretation in and around Anza-Borrego Desert State Park through programs, exhibits, and community engagement. Media Contact: ABDNHA Desert Nature Center 652 Palm Canyon Drive, Borrego Springs, CA (760) 767-3098 abdnha.org/gardentour
By Dennis Mammana Week of March 1-7, 2026 Attention, night owls and insomniacs! The sky show this week is just for you! Much of North America is about to see the moon experience one of nature's most beautiful sky shows: a total lunar eclipse. A lunar eclipse occurs when the full moon slips into the Earth's shadow far out in space, either partially or completely, and that's just what will happen during the wee hours of March 3. Skywatchers throughout North America will see the start of this eclipse (weather permitting, of course), but depending on where you live, you may see only a portion of the sky show. In general, the farther west you live, the more of the eclipse you will see before the moon sets behind the western horizon. The eclipse begins at 12:44 a.m. PST (3:44 a.m. EST), when the moon enters the Earth's light outer shadow (known as the penumbra), but this shadow is so thin that no one will notice a darkening of the moon's appearance. Within an hour or so, that will change significantly. As the moon approaches the dark inner shadow of the Earth (known as the umbra), skywatchers will notice the eastern side of the moon beginning to darken slightly. The real show begins at 1:50 a.m. PST (4:50 a.m. EST) when the moon officially enters the umbra. No one gazing skyward will have any doubt that a "bite" has been taken out of the moon — a bite that will grow larger with each passing minute. For the next hour or so, the moon will dim as it slips more deeply into our planet's umbra, until 3:04 a.m. PST (6:04 a.m. EST) when it's completely engulfed and the total eclipse begins. Unfortunately, those in the far eastern part of North America may miss this since the moon will lie quite close to (or even below) the western horizon. During the total phase, the moon will take on a dim coppery hue. This occurs because sunlight passing through our atmosphere is reddened and bent inward toward the darkened surface of the eclipsed moon, now suspended eerily against the stars of Leo, the lion. Only those viewing from the Midwest to the West Coast will see mid-eclipse, which occurs at 3:33 a.m. PST (5:33 a.m. CST). Those in the Midwest may miss the end of totality at 4:02 a.m. PST (6:02 a.m. CST), however, as the moon will be setting in the west. The entire event will end at 5:17 a.m. PST (4:17 a.m. MST) with the moon approaching the western horizon for viewers in western North America. Unlike an eclipse of the sun, a lunar eclipse is perfectly safe to view without protective filters. Your eyes are all you need to enjoy the show, but you'll have even more fun viewing through binoculars or a small telescope. If the sky is cloudy that morning, or if you live where the eclipse won't be visible, you can watch a livestream of the sky show online. Visit timeanddate.com and click on "Sun, Moon & Space" at the top to find details for your location, as well as links to view the eclipse live online. Visit Dennis Mammana at dennismammana.com. To read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com. Learn More About Borrego Springs
Among Eridanus’ prominent stars is Epsilon Eridani. Creators.com illustration
The Great Orion Nebula is visible with the unaided eye.
This segment aired on KTLA's Off the Clock on Jan. 7, 2026.
Borrego Springs, in San Diego County, is experiencing an unusual winter wildflower bloom. Henderson Canyon is already colorful—just about a 90-minute drive from San Diego. (ABDNHA)
Discover the exciting 2023-2024 activities offered by the Anza-Borrego Desert Natural History Association, including hikes, stargazing, conservation efforts, and educational programs. Join us to explore the wonders of the Anza-Borrego Desert.
Discover the ABDNHA Desert Garden and ArtPark Garden in Borrego Springs. These free, must-visit spots near Christmas Circle offer a unique blend of natural beauty and artistic expression. Perfect for nature and art lovers!
Discover the story behind the Hawkwatch documentary, showcasing the Swainson's Hawk migration, citizen science efforts in Borrego Springs, and the push for conservation.
Explore the best stargazing spots in Borrego Springs, California, with a stargazing map by the Dark Sky Coalition. Discover popular locations and tips for a perfect night under the stars.
Meet Dennis Mammana, a passionate astronomer with nearly five decades of experience in unraveling the mysteries of the cosmos. Dennis’s journey began in Easton, PA, where he was captivated by the launch of the first Earth-orbiting satellites in the late 1950s.
