Tuesday, July 23 Comet PANSTARRS (C/2011 L4) should glow around 11th magnitude this week, so you’ll need a good-sized telescope to follow its trek back into the outer solar system. Fortunately, it remains on view all night for observers in the Northern Hemisphere. Tonight and tomorrow night, the comet lies 5° east of the 8th-magnitude spiral galaxy M101. Wednesday, July 24 Shining at magnitude –1.9, Jupiter appears obvious in the predawn sky despite the presence of twilight. This week, the giant planet rises some two hours before the Sun and climbs 10° high in the east-northeast an hour later. A telescope will show you Jupiter 33"-diameter disk but not much detail thanks to the planet’s low altitude. The Southern Delta Aquarid meteor shower produces many faint meteors during its long active streak July 12–August 23. // Astronomy: Roen Kelly Thursday, July 25 The Southern Delta Aquarid meteor shower continues to ramp up this week. The shower has a broad maximum in late July, but you should see a few members in the hours before dawn. Unfortunately, a waning gibbous Moon currently shares the morning sky, reducing the number of meteors you can see. To tell a Southern Delta Aquarid meteor from a random dust particle burning up in Earth’s atmosphere, trace the streak of light’s path backward. A shower meteor will appear to originate from the constellation Aquarius the Water-bearer. Friday, July 26 The 10th-magnitude asteroid 6 Hebe remains among the background stars of Serpens the Serpent this week, a short star-hop from magnitude 3.5 Mu (μ) Serpentis. Tonight, Hebe lies 1° northwest of this star. Use a 4-inch or larger scope and a low-power eyepiece to track it down. To confirm a sighting, make a quick sketch of the star pattern and return to the same field a night or two later. The dot that moved is the asteroid. The winter stars return to the morning sky in late July. This year, Mercury, Mars, Jupiter, and the Moon enhance the scene. // Astronomy: Roen Kelly Saturday, July 27 Mercury joins the cavalcade of planets on display before dawn at the end of July. This morning, it lies 7° directly below Mars and appears 8° high in the twilight 30 minutes before sunrise. Fortunately, it shines a full magnitude brighter than its neighbor, which helps it stand out against the bright sky background. Sunday, July 28 As darkness falls these July evenings, Saturn lies nearly 30° above the southwestern horizon. The ringed planet shines at magnitude 0.6 among the background stars of eastern Virgo, where it sits less than 1° south-southeast of 4th-magnitude Kappa (κ) Virginis. Although a naked-eye view of the planet is nice, seeing it through a telescope truly inspires. Even a small instrument shows the distant world’s 17"-diameter disk and the spectacular rings, which span 39" and tilt 17° to our line of sight. The planet reaches quadrature today, which signifies that a line from the Sun to Earth and then to Saturn forms a right angle. Observationally, this means that Saturn’s shadow extends farthest east of the planet and shows up plainly on the rings, giving the world a striking 3-D appearance. Related Articles A pair of close encounters Southern Delta Aquarid meteor shower peaks at the end of July From Astronomy - The Sky this Week
Posted on: Tue, 23 Jul 2013 20:40:16 +0000
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