With the moon out of the night sky this week, some far-off treasures come to light. A planetary alignment with the stars adds to the delight.
Dumbbell Nebula. With the moon out of the evening sky for much of the week, this is a perfect time to hunt for deep-sky targets—celestial objects that lie outside our solar system.
One summertime favorite is a dying-star remnant known as the Dumbbell Nebula or Messier 27. Located some 1,300 light-years from Earth, in the faint constellation Vulpecula, or Little Fox, it consists of a bubblelike gas cloud lit up by a small star at its center.
Glowing at a magnitude of 7.5, the Dumbbell is a fairly easy target for backyard telescopes.
To spot it (see star chart below): First identify Albireo, the head star of the constellation Cygnus, the Swan. Then find the star Rotanev, one of the faint naked-eye stars of the tiny constellation Delphinus, the Dolphin.
Finally, draw an imaginary line between the two stars, and about a third of the way down from Albireo is the Dumbbell Nebula. Once you’ve located the tiny gray, ghostlike cloud in a low-power eyepiece, shift to a higher magnification to see its subtler details.
Aquarids Peak. The predawn hours of July 29 and 30 will be the best time to look for this annual minor meter shower. Usually outdone by their August cousins, the Perseids, the Aquarids will put on a better sky show this year, since their peak will be during a new moon.
Check our detailed viewer’s guide.
Worth noting are the differences in the color of these starlike objects. Spica, which is some 250 light-years from Earth, shines with a distinct blue-white light. It actually consists of two stars that orbit each other once every four days. Mars, which is some ten light minutes from Earth, shines with a distinct orange hue, thanks to all the iron-oxide-rich, dusty soil that covers its surface.
Saturn, 81 light minutes from Earth, is a yellow-hued cosmic beacon.
Lunar Sandwich. By the next evening, Saturday, August 2, the moon will have slipped between Spica and Mars for sky-watchers in the Northern Hemisphere.
It just goes to show you that the moon will stay out of the picture only for so long.