StarWatch: Moravian College Astronomy

StarWatch for the greater Lehigh Valley

JANUARY 2015

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

Print Large Sky Charts For 9 p.m. EST: NORTH | EAST | SOUTH | WEST | ZENITH

Current Solar X-rays:

Current Geomagnetic Field:

958 DECEMBER 28, 2014: 2015: A Good Year for Astronomy: Looking ahead to the New Year is always a fun activity, and although 2015 will not be as spectacular as 2017, when a total solar eclipse sweeps diagonally across the US (August 21), it does hold the promise for some very enjoyable sights including the highlight of the year, a total lunar eclipse on the evening of Sunday, September 27. First contact with the Earth’s main shadow happens at 9:07 p.m., EDT; totality occurs between 10:10 and 11:24 p.m., and final egress from Earth’s umbra happens by 12:27 a.m. Monday. The altitude of the moon ranges from 26 degrees at the onset of the eclipse to just over 50 degrees at its conclusion, so finally after many years of witnessing morning, tree-hugging eclipses, we’ll have a lunar eclipse that takes place at a relatively decent hour, and at a height where trees and buildings should pose few problems. If you want to see planets, the first half of 2015 is perfect. Jupiter is in prime evening viewing from January through June, and Saturn from mid-May through early September. Both Venus and Mercury have beautiful evening apparitions during the spring. On May 7 Mercury sets nearly two hours, and Venus almost four hours, after sundown. During twilight, Mercury, Venus, and Jupiter will be strung out like glistening pearls against the darkening evening sky. By June 30 Venus and Jupiter stand only 1/3rd degree apart, a splendid visual or telescopic sight. Venus is also visible in the morning sky throughout much of the fall, but between October 26 and November 3, Venus, Mars, and Jupiter do-si-do high in the dawn sky. Meteor showers with respect to morning moonlight are nearly perfect for 2015. Perseid meteors fly August 13, one day before new moon; the Orionids, October 21, one day after first quarter; the Leonids, November 18, with a six-day old moon in the sky, and the Geminids, December 14, with a thin waxing crescent moon. To tell you the truth, 2015 is really not that bad. Clear skies to everyone in the New Year!

959 JANUARY 4, 2015: Mercury and Venus Tango in the Evening Sky: The first full week of the New Year begins January 4, with a full moon in the ENE, two bright planets low in the SW, not including Mars and Neptune, and a comet that has suddenly brightened and is headed rapidly northward from its debut in the Southern Hemisphere. That’s not a bad opening to what was already shaping up to be a good year. See last week’s StarWatch at astronomy.org. Because the bright moon will be lighting up the evening sky for a good part of this week, and Comet Lovejoy, C/2014 Q2, is just becoming visible to the unaided eye under a dark sky, Mercury and brilliant Venus get first billing. At week’s start they are about six degrees above the southwestern horizon, 30 minutes after sundown and only 2-1/2 degrees apart, a very comfortable fit in binoculars. Use binoculars to help spot fainter Mercury in bright twilight. The main key for success is finding a nearly perfect SW horizon, one that is not obscured by trees, buildings, or possessing bright streetlamps. Oftentimes highrise apartments with good western exposures, even in urban locales, are excellent settings for these types of observations. By week’s end, January 10, Mercury and Venus have moved to their closest distance, just over one moon diameter apart, which is now a comfortable fit in virtually any telescope at low to medium magnifications. In addition, Mercury and Venus will have gained three more degrees in altitude, and this slow climb will continue throughout the following week. By January 17 the pair are once again separated by 2-1/2 degrees, but are now 10 degrees above the horizon in the SW, 30 minutes after sundown. A thin waxing crescent moon accents the Mercury-Venus scene on January 21 and is near Mars the following evening. Mars and Neptune (invisible) are above and left of Mercury and Venus during this entire apparition. A map can be found online at astronomy.org in “this week’s StarWatch.”

960 JANUARY 11, 2015: Comet Lovejoy: Just What the Doctor Ordered: I saw it just a few days ago with a nearly full moon in the sky. Comet Lovejoy, C/2014 Q2, is here, and although it is not a barn burner, it is visible through binoculars; and now with the moon on the wane, it should become visible to the unaided eye from rural locales and maybe even to suburbia. Discovered on August 17, 2014 by amateur astronomer Terry Lovejoy of Thornlands Queensland, near Brisbane, Australia, C/2014 Q2 is the fifth comet to bear the Lovejoy name and his third in a row to reach naked eye visibility. Lovejoy’s most famous comet, C/2011 W3, was a sungrazer which passed through Sol’s corona. Unlike the Thanksgiving (2013) Comet ISON debacle, another sungrazer that disintegrated after closest approach, Lovejoy W3, emerged in late 2011 as a spectacular visual treat for Southern Hemispheric observers. C/2014 Q2 was predicted to be much dimmer, in fact, nothing more than a faint binocular or telescopic object at its brightest; but it has proven to be an overachiever, becoming binocular in December and now visual from dark observing sites. Whether this newest Lovejoy discovery is slated for naked eye visibility from suburban skies should be known this week or next as the comet puts on its brightest show. To see Lovejoy, use binoculars. A map showing Lovejoy’s position throughout January is provided in the web version of “this week’s StarWatch” at astronomy.org. Currently (Jan. 11-17), the comet is due south at 8 p.m. and will be passing through the constellation of Taurus the Bull to the west (right) of the bright star Aldebaran by about three binocular fields. Later in the week, Lovejoy also approaches the famous Pleiades or Seven Sisters star cluster on the shoulder of the Bull. Follow the three belt stars of Orion the Hunter upward to Aldebaran and the “V” shaped head of Taurus and onward to the Seven Sisters. When viewing through binoculars, the comet will have a cottony, fuzz ball like look and may even appear elongated.

961 JANUARY 18, 2015: Comet Lovejoy Brightens: During the past week I have had several opportunities to view brightening Comet Lovejoy, C/2014 Q2. On Tuesday, January 13, it appeared as distinctive from a suburban locale as it had appeared on Saturday evening from a more rural place. Once Lovejoy was spotted with binoculars, it was easy to relocate again and again. My less than perfect eyes have not been able to see the comet unaided, although other observers have been able to view Lovejoy with just the naked eye from rural settings. Through binoculars, C/2014 Q2 appears like a fuzz ball growing slightly brighter towards the center. It’s big, about the size of the moon, so there is no missing it once you’ve found it. On January 15, with binoculars, I was able to see a faint tail that I had recorded earlier in photos before the comet brightened. In images Lovejoy has a distinct greenish hue, due to the fluorescence of C2, a molecule composed of two carbon atoms. The electrons of the C2 molecule absorb invisible ultraviolet radiation from the sun causing the carbon to become either ionized or excited. When electrons are captured and/or return to a lower energy state, some of the transitions produce radiation that we can see. In addition, dust also reflects and scatters sunlight which enhances the comet’s brightness. Lovejoy’s light is being produced more by gases than by dust. Gritty comets, like Hale-Bopp seen in the spring of 1997, produce the most memorable events; however, C2 emissions occur right around the greatest sensitivity of the human eye, so not all is lost. If you’d like to see Comet Lovejoy, “now” represents the best opportunity. Click on “this week’s StarWatch” at astronomy.org to view a map through the end of January. The comet will be within two to three binocular fields of view of the Pleiades through January 24, but watch out; the moon returns to brighten the landscape starting around the 25 of January when it will be passing close to the comet.

962 JANUARY 25, 2015: More Daylight, Please: I am already into the second week of the spring term and almost two months beyond the date of the earliest sunset. That was on December 8, when Sol set at 4:34 p.m. at 40.5 degrees north latitude. I was wrapping up the fall term on that date for one of my classes. The days continued to shorten until the winter solstice (sun standstill) on December 21, despite the fact that sunsets were occurring just a little later each evening. Finally on January 5, we reached the latest sunrise at 7:25 a.m., so that after that date, each successive sunrise occurred earlier, and each sunset happened later. Another milestone had been reached in my mental quest to bring summer around as quickly as possible. Well, as everyone knows, it’s not quite that simple. The Earth plods along in its orbit around the sun about one degree each day, and the axis remains tilted at the same angle. This constancy means that, astronomically speaking, there is no way of rushing things. Eventually, the sun will cross the celestial equator and favor the Northern Hemisphere on the vernal equinox, March 20; but even in late January with a substantial chance of snowfall still lying ahead, progress is being made. As an example, by the end of this week, sunset will be occurring at 5:18 p.m., a gain of 44 minutes over the earliest sunset. Sunrise happens at 7:12 a.m., thirteen minutes earlier than the latest sunrise. Add these two numbers together and we’ve gained almost an hour of precious daylight. It’s a healthy start, although we still have five more hours of sunlight to gain between now and the summer solstice on June 21. The biggest boost to my hopefulness that spring will return has nothing to do with an increase in daylight. It is daylight’s redistribution so that we get more of it while we’re awake. Our switch from standard to daylight time takes place on the second Sunday in March which just happens this year to be as early as it can get, 2 a.m. Sunday, March 8.

[January Star Map]

[January Moon Phase Calendar]