Seeing Stars with James Wooten: Five planets at dawn, leap day this February!

Star Map

Jupiter is now a late evening object, rising in the east. It rises by 9 p.m. on Feb. 1, and by Feb. 29 it comes up just before 7 p.m., which is during evening twilight. Jupiter comes to opposition on March 8, which is when Earth aligns with Jupiter and the Sun. That is why Jupiter is up all night long in late February and early March.

As dawn approaches this month, Jupiter will still be visible, this time high in the west.  Meanwhile, the four other visible planets will have risen as well. That’s right, February 2016  features all five naked-eye planets at dawn!

Venus is in the southeast at dawn. You can’t miss it, as Venus outshines all the stars we see at night, and in fact outshines everything but the Sun and the Moon.

Mars is in the south at dawn. Noticeably reddish in tint, Mars continues to brighten each day until its opposition next spring. 

Saturn is in the south southeast at dawn, above the distinctive pattern of Scorpius, the scorpion. Mars slowly approaches Saturn this month.

Mercury is the biggest challenge to find. This month, though, Mercury is very close to Venus and to its left. Thus, once you find Venus, the brightest dot to its left is Mercury. 

Mercury is the first planet to leave the gathering as it heads back towards the Sun late this month. The cutoff date of Feb. 20 is somewhat arbitrary, though. It’s better to watch the sky and, using Venus as your guide, see for yourself when is the last day you can still see Mercury before losing it the Sun’s glare. The next to leave is Jupiter, which shifts into the evening sky after opposition. 

Taurus, the Bull, is high in the south. Look for the Pleiades star cluster above reddish Aldebaran. Dazzling Orion, the Hunter, takes center stage on winter evenings.  Surrounding Orion are the brilliant stars of winter. Orion’s belt points down to Sirius, the Dog Star, which outshines all other stars we ever see at night. The Little Dog Star, Procyon, rises with Sirius and is level with Orion’s shoulder as they swing towards the south. To the upper left of Orion’s shoulder is Gemini, the Twins.

Under Sirius and low to the southern horizon this month is a star that most Americans never get to see—Canopus. Representing the bottom (keel) of the legendary ship Argo, Canopus is the second brightest star ever visible at night. Thus, it is clearly noticeable along the southern horizon on February and March evenings. However, you must be south of 37 degrees north to see Canopus rise. (This is the line that divides Utah, Colorado, and Kansas from Arizona, New Mexico, and Oklahoma.)

The sky we see depends on our latitude as well as on the time of night and time of year.  From any given location in our hemisphere, there is an area of the sky around the North Star in which stars never set (circumpolar stars), and an equivalent area around the South Celestial Pole in which stars never rise. The closer you are to the pole, the larger these areas are. The closer you get to the equator, the fewer circumpolar stars there are, but there are also fewer stars that never rise for you. At the equator, no stars are either circumpolar or never visible; all of them rise and set as Earth turns. 

That’s why, down here in south Texas, the Big Dipper sets for a while although it’s always up for most Americans. On the other hand, Canopus, too far south to rise for most Americans, rises for us.

Moon Phases

Moon Phases in February 2016:

Last Quarter: Jan. 31, 9:28 p.m.

New: Feb. 8, 8:39 a.m.

First Quarter: Feb. 15, 1:46 a.m.

Full: Feb. 22, 12:20 p.m.

(February is so short that last quarter Moons occur on Jan. 31 and March 1, but not in February). 

The New Moon of Feb. 8 is the second New Moon after the winter solstice. Accordingly, it marks Chinese New Year. Welcome to the Year of the Monkey!

Monday, Feb. 29, is leap day. This day exists because our normal year of 365 days is too short. The true length of one Earth orbit around the Sun is 365 days and almost 6 hours.  No one wants to begin a year in the middle of a day, however. Therefore, we let the error add up over four years, until it becomes 24 hours, or one whole day, then add that day back to the calendar. Thus, February 29 occurs every four years. 

Almost 6 hours?  Well, alright, the difference between our orbit and our year is actually 5 hours, 49 minutes, and 16 seconds. That makes our system a very slight overcorrection.  To prevent that from adding up, we’ll skip leap day in 2100, 2200, and 2300. 

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement. 

Clear Skies!

Seeing Stars with James Wooten: Four Planets are Visible

jan star report

Venus is in the southeast at dawn, approaching Saturn. Venus passes Saturn the morning of January 9; the two planets are less than one tenth of one degree apart! They’re easy to tell apart, as Venus outshines all the stars we see at night and is almost 100 times brighter than Saturn.

Mars is now in the south at dawn. Much dimmer than Venus now, Mars is getting a little brighter each day until its opposition next spring.

Jupiter now dominates the southwestern sky at dawn. As Jupiter approaches its opposition on march 8, you can also begin looking for it in late evening. By January 31, for example, Jupiter rises by 9:00 and will have cleared most horizon obstacles by 9:30 or 10.

In January, the Big Dipper is only partly risen at dusk. As the Big Dipper rises, though, Cassiopeia remains high. This is a pattern of five stars in a distinct W (or M) shape which lies directly across the North Star from the Big Dipper. Look for Cassiopeia high in the north on fall and winter evenings.

Watch for the Great Square of Pegasus in the west at dusk. Taurus, the Bull is high in the south. Look for the Pleiades star cluster above reddish Aldebaran. Dazzling Orion, the Hunter takes center stage on winter evenings. Surrounding Orion are the brilliant stars of winter. Orion’s belt points down to Sirius, the Dog Star, which outshines all other stars we ever see at night. The Little Dog Star, Procyon, rises with Sirius and is level with Orion’s shoulder as they swing towards the south. To the upper left of Orion’s shoulder is Gemini, the Twins.

Moon Phases
Moon Phases in January 2016:

Last Quarter Jan. 1, 11:30 p.m.; Jan. 31, 9:28 p.m.

New Jan. 9, 7:31 p.m.

1st Quarter Jan. 16, 5:26 p.m.

Full Jan. 23, 7:46 am

At 4:49 pm on Saturday, January 2, the Earth was as close to the Sun as it will get this year. Thus we say that the Earth was at perihelion. However, Earth was only about 1.6% closer to the Sun than average on this date. That’s why being closer to the Sun at this time does little to warm us up. The effect of Earth’s tilt on its axis dominates the small effect of Earth’s varying distance in causing the seasons.

Although the shortest day (least daylight) occurs on December 21, the latest sunrise occurs for us about January 10. That’s because the Earth speeds up on its orbit as it approaches perihelion. This acceleration shifts sunrise, local noon, and sunset slightly later each day for the first part of this month. The effect is smaller than that of the Sun taking a slightly higher path across the sky, which normally dominates in causing later sunsets and earlier sunrises. But the Sun’s apparent path varies very little near the solstice itself, allowing the secondary effect of the Earth approaching the Sun to predominate until mid-January. Most people, then, will notice that both sunrise and sunset are now happening earlier than in December. As we move farther from the solstice, the effect of the Sun taking a slightly higher path each day again predominates.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement.

Clear Skies!

Seeing Stars with James Wooten: Southern sky brings beasts and gods of water in November

November Sky

Saturn sets in twilight for the first week of November and is lost in the sun’s glare the rest of the month. 

Venus, Mars and Jupiter are still close together in the morning sky this month. Right now, Venus is close to Mars, with Jupiter above them. Venus and Mars are 0.68 degrees apart the morning of Nov. 3. Venus is brighter than Jupiter, and both outshine all stars we ever see at night, so they’re easy to find even in twilight. Mars is much, much dimmer than those two. The moon is near Jupiter on Nov. 6 and near Venus on Nov. 7. During this month, watch as Venus pulls away from Mars and both pull away from Jupiter. 

Autumn represents a sort of ‘intermission’ in the sky, with bright summer stars setting at dusk, while bright winter patterns such as Orion won’t rise until later (Orion is up by about 10 p.m. now and about 9 p.m. mid-month). The Summer Triangle is in the west.   Meanwhile, the Great Square of Pegasus is almost overhead. The stars in the southern sky are much dimmer than those overhead and in the west because when you face south at dusk in November, you face out of the Milky Way plane. The plane of our Galaxy follows a path from the Summer Triangle in the west through Cassiopeia in the north and over to the northeastern horizon.  

Constellations in the November southern sky represent beasts and gods related to water, indicating that they are part of the ‘Celestial Sea.’  Examples are Aquarius, the Water Bearer and Pisces, the Fish.  Even Capricornus, the Goat, has a fish tail because he’s originally Ea, Babylonian god of the waters. Below Aquarius is Fomalhaut, marking the mouth of the Southern Fish. Ancient Mesopotamians imagined that the Persian Gulf extended upwards into the sky, joining this ‘sea’ of dim stars.

Moon Phases

Moon Phases in November 2015:

Last Quarter: Nov. 3, 6:24 a.m.

New: Nov. 11, 11:47 a.m.

First Quarter: Nov. 19, 12:27 a.m.

Full: Nov. 25, 4:44 p.m.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement.

Clear Skies!

 

Seeing Stars with James Wooten: Planets near alignment, Astronomy Day arrives, and the clock ‘falls back’ this October

October Seeing Stars

Saturn is now in the southwestern sky at dusk. It outshines the stars around it, so it’s also easy to see. By Halloween night, however, Saturn sets in twilight; it drops into the Sun’s glare next month. 

Venus, Mars, and Jupiter will come close together in the sky late this month. Right now, the three planets are almost in a vertical line, with Venus, Jupiter on the bottom, and Mars in between. Venus is brighter than Jupiter and both outshine all stars we ever see at night, so they’re easy to find even in twilight. Mars is much, much dimmer than those two. It is now just below (and slightly dimmer than) the star Regulus in Leo.  During this month, watch as Mars gains on Jupiter and Venus gains on them both. Mars overtakes Jupiter Oct. 17, when they are just 0.38 degrees apart. By way of comparison, your pinky held at arm’s length blocks about one degree. Venus then passes one degree from Jupiter Oct. 26. That morning, the three planets form the most compact alignment, fitting within a circle 3.35 degrees across. Venus goes on to overtake Mars the morning of Nov. 3. They are 0.68 degrees apart that morning.

The Big Dipper is left of the North Star, with its handle pointing up. From that handle, you can ‘arc to Arcturus’ in the west at dusk. 

Autumn represents sort of an ‘intermission’ in the sky, with bright summer stars setting at dusk, while bright winter patterns such as Orion have not yet risen. The ‘teapot’ of Sagittarius sets in the southwest early in the evening. The Summer Triangle is high in the west. Meanwhile, the Great Square of Pegasus is in the east, indicating that autumn has begun. The stars rising in the east are much dimmer than those overhead and in the southwest because when you face east at dusk in October, you face out of the Milky Way plane. The center of our galaxy lies between Scorpius and Sagittarius, while the Summer Triangle is also in the galactic plane. Pegasus, on the other hand, is outside the plane of our galaxy and is a good place to look for other galaxies. Nearby constellations Andromeda and Triangulum (a small triangle) contain the spiral galaxies nearest to our own.

Moon Phases

Moon Phases in October 2015:

Last Quarter: Oct. 4, 4:06 p.m.

New: Oct. 12, 7:06 p.m.

1st Quarter: Oct. 20, 3:31 p.m.

Full: Oct. 27, 7:05 p.m.

Our annual Astronomy Day at the George Observatory is Saturday, Oct. 24! On Astronomy Day, we have activities from 3 to 10 p.m., and all of the telescopes, even the ones that normally cost $5 to look through, are free. It’s the biggest astronomy event in southeast Texas! Click here for more information.

Halloween is on Saturday this year, which means that the next day, Nov. 1, is the first Sunday of November. Therefore, Daylight Saving Time ends and we ‘fall back’ to standard time at 2 a.m. that morning. (The time goes from 1:59 a.m. back to 1 a.m., giving us the 1 a.m. hour twice.) So get your #ChillsAtHMNS, don’t forget to set your clocks back, and enjoy your extra hour of sleep Halloween night!

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement. 

Clear Skies!