THIS MONTH'S SKY - June 2010

THIS MONTH'S SKY
Celestial Events -- June 2010

 

SPOT URANUS NEXT TO JUPITER

Uranus, the seventh planet from the Sun, is normally difficult to find.  At magnitude around 6, it should be visible to the naked eye at a dark site, and with binoculars from the city.  However, many stars are as bright or brighter -- the difficulty is finding which one is Uranus. That will not be a problem this month, for next to Uranus is the brilliant planet Jupiter.  Unfortunately, the two planets don't rise until after midnight this month, and at the start of the month you'll have to wait until after 2 AM!  (By the end of June they will rise around 12:30 AM.)  But if seeing Uranus is important to you, now is the time. Look in the east for Jupiter.  It is the brightest object in the sky after the Moon.  The Moon will be very bright early in the month, providing some difficulty, but by June 8, the time Uranus and Jupiter are closest, the Moon is a small crescent that should not interfere. Use Chart 1 to find Uranus on the date in question.  Jupiter and Uranus will be less than 1° apart from June 1 to 16.  They will be less than ½° apart from June 6 to 10. Use Chart 2 on the morning of the 8th, when the planets are closest, only 26' apart (for comparison the diameter of the Sun or Moon is about 30').  On that date using binoculars or a telescope with a low- to medium-power eyepiece, you should see both planets as well as Jupiter's four bright moons, all in the same field of view. If you can, look closely at Uranus with a high-power eyepiece.  You should notice Uranus is a small blue-green ball rather than a point of light.  It really is a planet.  Happy hunting!

Chart 1 Uranus and Jupiter June at 3 AM Chart 2 Jupiter and Uranus 3 AM June 8

A COMET IN THE MORNING SKY

Besides Jupiter and Uranus, another object visible in the wee hours is Comet C/2009 R1 McNaught, discovered by Robert McNaught of Siding Spring Observatory in Australia on September 9, 2009.  (The name indicates the comet was the first one discovered in the first half of September 2009.) The comet is inherently pretty bright, and would not be a difficult target for a scope if it were well up in the sky.  Unfortunately, the comet will be low on the horizon until morning twilight begins.  The best viewing time is around 3 AM, when the sky will still be dark and the comet about 15° above the horizon.  The comet will spend June moving to the north (see the chart to the right).  It brightens during the month but gets lower as the month proceeds..

Comet C/2009 R1 McNaught June 3 AM

The following descriptions are for 3 AM.  All references to magnitude are estimates -- the comet may be brighter or fainter.  For the first nine days of June, a bright Moon will also be a problem.  After that it will not be a hindrance.

On June 1st the comet is predicted to be magnitude 7.8.  On that evening it will be 3½° below left of the second-magnitude star Beta β Andromedae.  You will need a dark sky and a good telescope to see the comet, especially since the Moon will be up.  Five days later (June 6) the Moon will be less of an interference, and Comet McNaught at magnitude 7.2 will be 2° below Alpha α Andromedae (Almach), a lovely double star. 

By June 10 the Moon is out of the picture. On that evening the comet (mag 6.7) is in Perseus, 1° from the open cluster M34.  On the 14th (mag 6.2) it passes through the large Alpha Persei Cluster.  From a dark site it should be lovely to see in binoculars.

Each day afterwards the comet will be harder to spot, as it is getting lower and dawn begins earlier.  On the 21st McNaught (mag 5.3) passes brilliant Capella, and three days later (mag 4.9) Beta Aurigae.  Though theoretically at maximum brightness now, the brightening sky makes it more and more difficult to see the comet.

The chart to the left shows the region of sky the comet passes through.  The direction and estimated length of the comet's tail are indicated.

For the continuing adventures of Venus, Mars and Saturn, see This Month's Sky for May.
 

JUNE'S EVENING SKY

Click to get sky charts and a description of the sky for this month.
 

PLANETS IN JUNE

MERCURY is in the morning sky almost all of June, but is visible only the first ten days, and probably seen only with binoculars.  Early in the month it rises one hour before the Sun, though that doesn't translate into much distance, since the angle of the ecliptic is unfavorable in the morning this time of year.  On the 11th Mercury will be 6° to the right of a very thin crescent Moon.  After that Mercury is swallowed up by the Sun's light.  It is at conjunction on the 28th, entering the evening sky.

URANUS (magnitude +5.8, diameter 3.5") is in Pisces.  Jupiter is 1° to Uranus' right (west) as June begins, and 2° to its left at the end of the month.  In between it passes only 26' above Jupiter on the morning of the 8th (see above).

NEPTUNE (magnitude +7.9, diameter 2.3") is in western Aquarius.

PLUTO (magnitude +14.0, diameter 0.1") is still in western Sagittarius.
 

THIS MONTH'S EVENTS
(Times in EDT)