Special to CosmicTribune.com, September 29, 2024

Excerpts from weekly Sky&Telescope report.

SUNDAY, SEPTEMBER 29

■ Face south and look high these evenings after dark. The brightest star there is Altair, the southernmost point of the Summer Triangle. The other two are Deneb and Vega more nearly overhead.

MONDAY, SEPTEMBER 30

■ The starry W of Cassiopeia stands high in the northeast after dark. The right-hand side of the W (the brightest side) tilts up.

Look at the second segment of the W counting down from the top. It’s not quite horizontal. Notice the dim naked-eye stars along that segment (not counting its two ends). The brightest of these, on the right, is Eta Cassiopeiae, magnitude 3.4. It’s a remarkably Sun-like star just 19 light-years away. But unlike the Sun it has an orange-dwarf companion, magnitude 7.3, separation 13 arcseconds — making it a lovely binary in a telescope.

Left of Eta, and quite a bit fainter, is a naked-eye pair in a dark sky: Upsilon¹ and Upsilon² Cassiopeiae, 0.3° apart, magnitudes 4.8 and 4.6. They’re yellow-orange giants unrelated to each other, 200 and 400 light-years distant from us. Upsilon² is slightly the brighter of the pair. It’s also the closer one.

TUESDAY, OCTOBER 1

■ Vega is the brightest star barely west of overhead after dark. To its right when you face west and look up, by 14° (nearly a fist and a half at arm’s length), you’ll find Eltanin, the nose of Draco the Dragon. The rest of Draco’s fainter, lozenge-shaped head is a little farther behind. Draco always eyes Vega as they wheel around the sky.

In the other direction, Draco’s long, arched back and tail loop around the Little Dipper.

The main stars of Vega’s own constellation, Lyra — faint by comparison — extend from Vega in the opposite direction from Eltanin.

WEDNESDAY, OCTOBER 2

■ One of the brightest very red stars for binoculars is the carbon star TX Piscium. It’s in the eastern edge of the Circlet of Pisces, which is a little south (lower right) of the Great Square of Pegasus. TX Psc is 5th magnitude visually, in easy binocular range. Carbon stars are especially red partly because we see them through a red filter: molecular C₂ vapor in their atmospheres.

Once you find the TX Cross, you’ll recognize it in the field of TX Piscium forever after.

■ New Moon today (exact at 2:49 p.m. EDT).

THURSDAY, OCTOBER 3

■ Globular clusters are at their most abundant on summer evenings. Now in this first week of October, with the night sky still moonless, set up your telescope to look in on four remaining ones that Josh Urban calls The Last Wildflowers: Globular Clusters Greet Autumn. There’s “Sagittifolia,” the Arrowhead Flower, M71 next to Sagitta; “Queen Anne’s Lace,” M15 sneezed from the nose of Pegasus; “Watercress by the Stream,” M2 in Aquarius a little farther south; and “Seaflower of the Deep,” M30 deep in southern Capricornus.

FRIDAY, OCTOBER 4

■ The Great Square of Pegasus balances on one corner high in the east through much of the evening. Two fists at arm’s length to the Square’s lower right shines Saturn, somewhat brighter.

Extending away from the Great Square’s left corner is the main line of Andromeda, three 2nd-magnitude stars about as bright as those of the Square and spaced similarly far apart. (The three include the Square’s corner itself.)

The low-riding waxing crescent Moon of early fall passes Venus, then Antares in the fading afterglow of sunset.

Venus is plotted here at its position on October 5th (for North America), when it’s 0.9° lower left of Alpha Librae, magnitude 2.8. Every day Venus moves 1.3° farther to the upper left with respect to the star. You’ll definitely need optical aid for this; Alpha Lib is only 1/500 as bright as Venus!

SATURDAY, OCTOBER 5

■ About a half hour after sunset, find the thin waxing crescent Moon paired with Venus very low in the southwest as shown above. They’re about 4° apart. A much harder catch is faint Alpha Librae, just under 1° to Venus’s upper right this evening.

SUNDAY, OCTOBER 6

■ After dark look just above the northeast horizon — far below high Cassiopeia — for bright Capella on the rise. How soon Capella rises, and how high you’ll find it, depend on your latitude. The farther north you are, the sooner and higher.

  Sept. 30-Oct. 7, The Sky