July 31, 2021: The slightly gibbous moon, nearing its Last Quarter phase, is in the southeast as morning twilight begins. It is near the planet Uranus, easily within reach of a binocular. Mira, a variable star, reaches its brightest next month.
by Jeffrey L. Hunt
For sky watchers who want to look for seemingly obscure celestial wonders, the moon points the way to them this morning.
Step outside with a binocular around the beginning of morning twilight that occurs about 2 hours before sunup. The moon is nearing its Last Quarter phase. This morning it is 51% illuminated. It is about halfway up in the east-southeast at this hour.
The Pleiades star cluster, the Seven Sisters, is to the left of the moon. The star Aldebaran, “the follower,” is below the star cluster. The star uses the Hyades star cluster as a backdrop. Aldebaran and the Hyades make a sideways “V” shape.”
Use the “V” pattern as an arrow to point to the right toward a trio of stars in Cetus, the Sea Monster. The stars are Menkar – “the nostril” – Gamma Ceti (γ Cet on the chart), and Delta Ceti (δ Cet).
The variable star Mira is to the right of the small triangle made by the three identified stars and over 13° to the lower right of the moon.
The star pulsates – changes size – as it changes brightness. Most of the time the star is beyond the limit of eyesight and at the limit of what can be seen with a binocular. About every 330 days, the star reaches its peak brightness that is easily observed in a dark sky without an optical assist. The star is expected to reach its brightest for this cycle around mid-August.
Mira is now visible without optical assistance to the right of the stars and the moon identified on the chart above.
The planet Uranus is visible with a binocular this morning. The moon is 8.5° to the right of the planet. The star is in a middle of a faint triangle of stars in Aries.
Through a binocular the planet has an aquamarine color. A telescope is needed to see its globe. Look for it this morning as the moon is nearby. As the moon moves eastward each morning and the sky darkens from its waning phase, the stellar triangle becomes easier to discern.
Attempt to find these two interesting celestial wonders.
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