StarWatch: Moravian University Astronomy

JANUARY 2026

JANUARY STAR MAP | MOON PHASE CALENDAR | STARWATCH INDEX | NIGHT SKY NOTEBOOK

lunar phases

1533 JANUARY 4, 2026: It's All Up From Here: Early January is usually a busy time if you are a meteor enthusiast because the second most abundant shooting star event of the year, the Quadrantid Meteor Shower, occurs on the morning of January 3. In 2026, it is also the night of the full moon, reducing rates from 80 meteors per hour from a rural, moonless site to perhaps five or fewer from a suburban moon-drenched locale. Do not fret; the 2027 Quadrantids will be much better. * Concurrent with the Quadrantids, Earth reaches perihelion eight hours later at 1 p.m. EST when it will be a scant 91,400,000 miles from the sun. Sol's average distance from the Earth is 92,956,000 miles, putting the Earth 1,556,000 miles closer, at a location in Earth's orbit called perihelion. * Can you feel that extra solar energy radiating down on you three weeks before the traditionally coldest time of the year? You'd better answer no! That is the biggest misconception the public has about why we have seasons. People assume that summer occurs when Earth is closer to the sun while winter happens when we obtain our farthest distance from Sol. That is completely incorrect. * So why is it so cold when we are closest to the sun? The answer is really quite simple. Earth's tilted axis leans back, away from the sun during this closest approach. This condition forces the sun’s daily motion to be much lower in the sky, reducing the length of sunlight to just nine hours. The energy of Sol becomes less concentrated over the same area in comparison to a higher sun during summer. The spring and summer sun produce more concentrated energy as any flashlight will demonstrate when the beam shines directly on a the subject. In addition, the summer solstice provides six more hours of sunlight than the winter solstice at our latitude of 40 degrees north. As a result, Earth's heat budget during low sun runs at a deficit. More energy (heat) escapes into space than can be replenished during the shortened, low sunlight hours, and temperatures plummet. In conjunction with Earth's perihelion passage, the latest sunrise occurs at 40 degrees north latitude on January 4. The shortest day of the year transpired this past December 21, when the sun's direct energy was farthest south of the equator. However, the earliest sunset for 40 degrees north latitude happened on December 7, when sundown occurred at 4:35 p.m. EST. Likewise, the latest sunrise occurs about two weeks after the winter solstice. All of the gains in the slowly lengthening day have happened in later sunsets. That is about to change with earlier sunrises and later sunsets as the sun accelerates its northward move. * The imbalance between sunsets and sunrises stems from discrepancies in the movement of the real sun and a fictitious, uniformly moving sun that astronomers use to dictate the beat of our 24-hour day. * As the Earth orbits Sol, it takes 23 hours, 56 minutes to complete one spin. As the Earth moves counterclockwise in its orbit during this time, the sun moves eastward among the stars by about one degree each day. The extra four minutes to complete the 24-hour day result from the time needed for the sun to catch up and reach the same position in its due south position at noon. * Changes in the eastward motion of the sun result from its traveling northward in the spring and southward in the fall, as well as the increased orbital speed of Earth when it is close to the sun and reduced speed when it is farther away in the summer. During the past month or so, the eastward motion of the sun has been greater than the extra four minutes allowed to complete the solar day. The real sun is lagging behind the fictitious sun, causing sunrises to become increasingly later even after the winter solstice. However that all changes after January 4, as the sun's higher altitude begins to lengthen daylight from both ends, with earlier sunrises and later sunsets. We are on our way. Things are definitely looking up. Ad Astra!

1534

JANUARY 11, 2026: Happy Julian New Year

We just celebrated the Gregorian New Year not quite two weeks ago, but the Julian calendar is just marking the old New Year this week on Wednesday, January 14. This calendar is no longer followed for civil purposes but does help fix liturgical dates for certain Eastern Orthodox religions. It was not always that way. * Russia was one of the last European countries to transition its civil calendar from the Julian to the more modern Gregorian calendar (1918), followed by Greece (1923) and Turkey (1927). Saudi Arabia switched from its Islamic calendar to the Gregorian calendar in 2016. * When Julius Caesar brought Cleopatra to Rome in 46 BCE, it was likely that tagging along with her entourage was Sosigenes, her advisor and teacher in the sciences, including astronomy. Sosigenes worked with Caesar to reform the Roman lunar calendar, often misused by the Senate, into a solar calendar of 365.25 days. To account for the nearly extra quarter day that the tropical year entailed, a leap day was added to the end of February every four years. In order to rectify the old lunar calendar to celebrate the New Year on January 1, an extra 90 days were added to 46 BCE creating what was known as the Long Year. January 1, 45 BCE was the inaugural date of the new Julian calendar. * However, there was a problem with the calculations of Sosigenes. The difference between the actual tropical year (365.2422 days) and Sosigenes' 365.25-day year amounted to an overcorrection of 0.0078 day (nearly 27 seconds) which in 129 years equaled 1.0062 days. In short, the Julian calendar was gaining on the sun so that in 129 years the original date of January 2 would become January 1. * When the Council of Nicaea created the rules for the formulation of Easter in 325 CE, March 21 was established as the permanent ecclesiastical date for the vernal equinox. At that time, this date was a good fit for the sun's crossing of the vernal equinox. The exact rule was that Easter was to occur on the first Sunday after the Paschal Full Moon, defined as the 14th day of the lunar month. That date had to be on or after the vernal equinox, for which the Church established the fixed date of March 21 using ecclesiastical (church) calendars, not derived from astronomical observations. This formula allowed Easter to occur as early as March 22 and as late as April 25. * At the time of the reformation of the Julian calendar in 1582 CE by Pope Gregory XIII the sun's crossing of the vernal equinox had slipped backwards by 10 days from March 21 to March 11. This caused the dates of Easter to migrate farther away from the true vernal equinox into later spring because the Church had fixed the date of the vernal equinox as March 21 whether it occurred on that date or not. This discrepancy was corrupting the original intent of the 4th century Council of Nicaea. To bring the dates of Easter into better seasonal agreement with the formula for calculating its date, Pope Gregory erased 10 days in 1582. October 5 became October 15. In addition, only century years divisible by 400 without a remainder would become leap years. The Gregorian calendar became accurate to one day in 3236 years. Not to worry any time soon about any calendar misalignments. However, somewhere around the century year of 4800, there might be two leap year days, February 29 and 30th added to that year's calendar. For all the Julians, a happy and productive New Year. Ad Astra!

1535 JANUARY 18, 2026: Phase Name Mania: I want to preface this blog with a thumbs up for the website https://www.timeanddate.com. I use it frequently. However while perusing its content recently, I came across phases of the moon with some unfamiliar names. These were not the standard Yule, Harvest, or Beaver moons many of us have come to know from either liturgical, historical, or Native American sources. Instead, they were labels like Super New Moon, Micro Full Moon, and Black Moon. * Most people realize that a supermoon (NASA spelling) represents a fully illuminated moon that is unusually close to Earth. Supermoons happen because Luna orbits in an oval-shaped (elliptical) path, getting closest to our planet or farthest from Earth every 27.55455 days. This period is called the anomalistic month and differs from the 29.53059-day synodic (phase) month. So each calendar month technically has a supermoon, but it's usually not in the moon's full phase. The moment of closest moon approach is called perigee, from the Greek peri, meaning near, and gee, Earth. Timeanddate labels the December 23, 2026 full moon as a supermoon. The distance to the moon at that time will be 221,600 miles. * However what about a Super New Moon which was a new term for me? This new moon is the closest to Earth when Luna is between Earth and the sun and cannot be seen unless a solar eclipse is happening. Should a moon that is invisible be lauded as a special event, and should there be more than one occurring each year? Timeanddate lists two Super New Moons in 2026: May 16 (222,800 miles distant) and June 14 (221,900 miles from Earth). * Then there is the Micro Full Moon which timeanddate hypes as a full moon occurring at Luna's greatest distance from Earth, apogee. Again, the word is derived from Greek, with apo meaning away and gee designating Earth. Timeanddate recognizes two Micro Full moons in 2026: the first on May 31 (252,500 miles from Earth) and the second on June 29 (247,500 miles distant). Clearly, there is an easy winner in the Micro Full Moon contest for 2026, so why have two? * Ironically, timanddate did not recognize any Micro New Moons in 2026, even though one clearly occurs on December 8, when the moon is new and 251,900 miles from Earth. What comes next—the super and micro first and last quarter moons? It's getting a little too complicated, all of these different moon names and dates to remember. * Don't forget the Blue Moon of May 31, 2026. This normal-looking moon has been an evolving term, first introduced in the Maine Farmers’ Almanac of 1937, linking full moons to events during the church year. When four full moons occurred within a seasonal three-month period, such as from the winter solstice to the spring equinox, the third full moon in that cycle became the Blue Moon. This practice kept the full moon names in step with the church liturgy. The more popular definition in the 21st century is simply the second full moon occurring within a single month. However, timeanddate now notes the Black Moon, two successive new moons that occur within one month. * Finally don't forget the Blood Moon, another term gaining traction for lunar eclipses. The eclipsed moon often has a reddish-brown hue when it is nearly or totally immersed in Earth's shadow. The East Coast gets to see two Blood Moons in 2026: a total lunar eclipse near dawn on March 3 and a deep partial lunar eclipse on August 27 into the morning of the 28th. Those dates are worth posting to your calendar. There are also two solar eclipses in 2026; however, neither one is visible from North America. * To everyone, best wishes for a prosperous year. Keep looking up, folks. It's a stress-reducing activity. Ad Astra!

1536 JANUARY 25, 2026: Apparent Magnitude: It's a Greek Thing: If a 5.5-magnitude earthquake occurs along a major California fault, and then a short time later a 6.5-magnitude event occurs in the same region, everyone knows the 6.5-magnitude event was larger than the first quake. In fact, the 6.5 magnitude quake would produce approximately 10 times more shaking amplitude based upon the logarithmic magnitude scale (base-10). In energy release, however, it would be about 32 times more potent. In astronomy, apparent magnitude represents how bright a star appears from the Earth, but the system is somewhat counterintuitive. If I look through a telescope at a double star with a 4.5-magnitude main component and an 8.6-magnitude secondary, the 4.5-magnitude star will outshine its 8.6-magnitude component by 4.1 magnitudes, or 44 times. The more negative the magnitude, the brighter the star. * The origin for this system dates back over 2000 years to the Greek philosopher, Hipparchus, who first attempted to quantify the brightness of stars subjectively. The system was based on his visual acuity, with approximately 20 stars chosen as first magnitude, the brightest luminaries, and sixth magnitude stars as the faintest that the human eye could perceive. * During the mid-19th century, an earnest attempt was made to quantify the system objectively. In one method, astronomers used an eyepiece containing a wedge-shaped filter that was moved internally until the star disappeared. The filter position provided an approximate magnitude determination. It was noted that the eye did not respond to changes in brightness (intensity) in a linear fashion. In other words, when the eye-brain subjectively perceived that one star was twice as bright as another star, the mathematics showed that it was actually 2.5 (2.512) times brighter. * When the system of apparent magnitudes was formalized, the Greek concept allowing more negative numbers to be assigned to brighter stars won the day. In addition, five magnitudes of difference, i.e., a first magnitude star compared to a much fainter sixth magnitude star, created an intensity difference of 100. Thus, the difference between each magnitude became the fifth root of 100 or 2.512 taken to three places to the right of the decimal. The fifth root of 100 is 2.512 multiplied by itself five times. * During the 19th century, precisions of about 1/10 of a magnitude could be obtained. Stars with magnitudes more positive than 1.5 and more negative than 2.5 were called second magnitude stars, etc. * To make the system absolute, Polaris, the North Star, was adopted in the Northern Hemisphere as a fundamental comparison star with a magnitude of exactly two. Today, we know that Polaris is a Cepheid variable with an average brightness of magnitude 1.99. Other systems used a series of fifth-magnitude stars near Polaris to calibrate a fixed visual-magnitude scale. Against this standardization, stars and planets could be assigned magnitudes of zero and negative numbers. Photographic techniques, stellar color biases, photoelectric determinations, charge-coupled devices (CCDs), orbiting satellites, atmospheric opacity, interstellar dust, and much more have all contributed to the growing accuracy of various methods for determining the visual or apparent magnitudes of stars. To paraphrase James B. Kaler, the author of The Cambridge Encyclopedia of Stars: Magnitude systems have multiplied like rabbits. Hipparchus lives. Ad Astra!