The Sky This Week for June 14 to June 19

A virtual who’s-who of our planetary neighbors will be out in the sky this week for you to find.

Tuesday, June 14

• Neptune’s eastward motion against the background stars comes to a halt at 4 a.m. EDT. This so-called stationary point marks the beginning of the best period to observe an outer planet. Neptune rises around 1 a.m. local daylight time and appears nearly 30° high in the southeast as morning twilight commences. The magnitude 7.9 planet lies in Aquarius, some 0.5° southeast of 4th-magnitude Lambda (l) Aquarii, and doesn’t move noticeably all week. You’ll need binoculars to spy Neptune and a telescope to see its blue-gray disk, which spans 2.3″.

Wednesday, June 15

• Mercury shines brightly in morning twilight this week, standing 6° high in the east-northeast a half-hour before sunrise today. The inner planet shines at magnitude –0.3 and shows up easily through binoculars if you have an unobstructed horizon. When viewed through a telescope, Mercury appears 7″ across and slightly more than half-lit.

• The Moon reaches apogee, the farthest point in its orbit around Earth, at 8:00 a.m. EDT. It then lies 251,670 miles (405,024 kilometers) from Earth’s center.

Thursday, June 16

• The conspicuous Summer Triangle asterism dominates the eastern sky in late evening. Vega, the triangle’s brightest member, shines at magnitude 0.0 and stands highest of the three stars. To its lower left lies Deneb; at magnitude 1.3, it’s the faintest of the trio. Magnitude 0.8 Altair completes the bright asterism. Despite its name, the Summer Triangle appears prominent from late spring until the onset of winter.

Friday, June 17

• The waxing gibbous Moon forms the apex of a flat isosceles triangle with Mars and Saturn tonight. The Moon stands highest and about 10° from both planets; Mars and Saturn lie approximately 18° apart.

Saturday, June 18

• The Moon passes 3° due north of Saturn at 8 p.m. EDT. For observers in North America, the two appear between 3° and 5° apart throughout the night.

Sunday, June 19

• Full Moon officially arrives at 7:02 a.m. EDT tomorrow morning, but it looks completely illuminated throughout the night. It appears low in the southeast as the Sun sets and reaches its peak in the south around 1 a.m. local daylight time. For North American observers, the Full Moon crosses from Ophiuchus the Serpent-bearer into Sagittarius the Archer during the evening hours.

Source

Astronomy Magazine

The Sun & Moon Data for Tuesday, June 14th

Sun
Sun Direction: ↑ 97.72° E
Sun Altitude: 50.32°
Sun Distance: 94.420 million mi
Next Solstice: Jun 20, 2016 5:34 PM (Summer)
Sunrise Today: 5:34 AM↑ 60° Northeast
Sunset Today: 8:16 PM↑ 300° Northwest
Length of Daylight: 14 hours, 41 minutes

Moon
Moon Direction: ↑ 36.88° NE
Moon Altitude: -52.81°
Moon Distance: 251402 mi
Next Full Moon: Jun 20, 20166:02 AM
Next New Moon: Jul 4, 20166:00 AM
Next Moonrise: Today3:02 PM
Current Moon Phase: Waxing Gibbous
Illumination: 71.3%

Source

timeanddate.com

While We Are Apart

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2016 June 13

Unexplained Dimmings in KIC 8462852
Illustration Credit: NASA, JPL-Caltech

Explanation: Why does star KIC 8462852 keep wavering? Nobody knows. A star somewhat similar to our Sun, KIC 8462852 was one of many distant stars being monitored by NASA’s robotic Kepler satellite to see if it had planets. Citizen scientists voluntarily co-inspecting the data along with computers found this unusual case where a star’s brightness dropped at unexpected times by as much as 20 percent for as long as months — but then recovered. Common reasons for dimming — such as eclipses by orbiting planets or stellar companions — don’t match the non-repetitive nature of the dimmings. A currently debated theory is dimming by a cloud of comets or the remnants of a shattered planet, but these would not explain data indicating that the star itself has become slightly dimmer over the past 125 years. Nevertheless, featured here is an artist’s illustration of a planet breaking up, drawn to depict NGC 2547-ID8, a different system that shows infraredevidence of such a collision. Recent observations of KIC 8462852 did not detect the infrared glow of a closely orbiting dust disk, but gave a hint that the system might have such a disk farther out. Future observations are encouraged and creative origin speculations are sure to continue.

Come to know the Summer Triangle

We in the Northern Hemisphere can see the Summer Triangle for part of the night at any time of the year. But seeing it in summer is the most fun! As suggested by its name, the Summer Triangle is most prominent during the summer season, for us at mid-northern latitudes. Although the Northern Hemisphere’s summer solstice won’t be forthcoming for another week, we can often see the Summer Triangle at evening dusk by mid-June. Seeing the Summer Triangle again and again on summer nights is a deep pleasure that adds to the enjoyment of this season. So, as dusk deepens into night on a warm June or July night, look eastward.

How to find the Summer Triangle. As night falls in June or July, look east for a sparkling blue-white star, whose name is Vega. Reigning at the apex of the celebrated Summer Triangle, Vega overwhelms as the brightest of the Summer Triangle’s three glorious stars, all bright enough to be seen from many light-polluted cities.

It’s difficult to convey the huge size of the Summer Triangle asterism – a star pattern that is not a constellation. At nightfall in summer, look for the brightest star in your eastern sky. That’s Vega, the brightest star in the constellation Lyra the Harp. Look to the lower left of Vega for another bright star – Deneb, the brightest in the constellation Cygnus the Swan and the third brightest in the Summer Triangle. An outstretched hand at an arm length approximates the distance from Vega to Deneb.

Look to the lower right of Vega to locate the Summer Triangle’s second brightest star. That’s Altair, the brightest star in the constellation Aquila the Eagle. A ruler held at an arm length fills the gap between these two stars.

Summer Triangle as a road map to the Milky Way. If you’re lucky enough to be under a dark starry sky on a moonless night, you’ll see the great swath of stars known as the Milky Way passing in between the Summer Triangle stars Vega and Altair. The star Deneb bobs in the middle of this river of stars that passes through the Summer Triangle, and arcs across the sky. Although every star that you see with the unaided eye is actually a member of our Milky Way galaxy, oftentimes the term Milky Wayrefers to the cross-sectional view of the galactic disk, whereby innumerable far-off suns congregate into a cloudy trail of stars.

Once you master the Summer Triangle, you can always locate the Milky Way on a clear, dark night. How about making the most of a dark summer night to explore this band of stars – this starlit boulevard abounding with celestial delights? Use binoculars to reel in the gossamer beauty of it all, the haunting nebulae and star clusters of a midsummer night’s dream!

Some see the Summer Triangle as a great big “V” for vacation, with Altair marking the point of the “V.” In summer, the Summer Triangle appears in the east at nightfall, high overhead after midnight and in the west at dawn. All night long on a summer night, the stars of the Summer Triangle – as if school kids on vacation – waltz amidst the streetlights of the Milky Way galaxy.

Summer Triangle as nature’s seasonal calendar. The Summer Triangle serves as a stellar calendar, marking the seasons. When the stars of the Summer Triangle light up the eastern twilight dusk in middle to late June, it’s a sure sign of the change of seasons, of spring giving way to summer. However, when the Summer Triangle is seen high in the south to overhead at dusk and early evening, the Summer Triangle’s change of position indicates that summer has ebbed into fall.

Bottom line: Coming to know the Summer Triangle, then seeing it again and again on summer nights, is a deep pleasure that adds to the enjoyment of this season.

Author

The Words of Confucius

Virtuous people often revenge themselves for the constraints to which they submit by the boredom which they inspire.