It is amazing to me how quickly this year is flying by. We are already well into the summer skies, and with the glorious weather we’ve been having here in the UK, the seeing has been especially good. Summer stargazing is harder than winter in the North due to the tilt of the Earth facing towards the Sun in the summer. This means longer days, shorter, brighter nights, and more humidity in the atmosphere, leading to more “wobble” when using telescopes and binoculars.

Despite the challenges, summer offers a chance to witness some of the most stunning constellations. In this episode of Stellar Cartography, I will explore Cygnus the Swan, Lyra the harp, and Aquilla the Eagle, three constellations whose brightest stars contribute to the breathtaking 'summer triangle'.

Cygnus the Swan.

Cygnus is relatively easy to spot. Looking straight up overhead, it is difficult to miss the obvious cross shape that the asterism makes, with the long neck and spread wings and tail of a swan in flight. It is a very old and well-observed constellation, one of the 48 recorded by the 2nd-century Greek astronomer Ptolemy. At the swan's tail, within the constellation is the most distant of the bright first-magnitude stars, Alpha Cygni or Deneb, a blueish-white Supergiant star some 2,600 light years away from Earth.



Like most stars, including our own, Deneb is a variable star, meaning its brightness fluctuates over time. Having exhausted its hydrogen, it now consumes helium to maintain the outward pressure necessary to prevent collapse. Over the next few million years, it is highly probable that Deneb will transform into a red Supergiant and culminate its existence in a grand supernova.

Other notable features within Cygnus include the Veil Nebula. The nebula is a 5,000-year-old supernova remnant that appears to stretch across the sky; it is, in fact, over 50 light-years in length. The nebula is best viewed via long-exposure photographs; however, it is possible to see the brightest parts using binoculars and telescopes.

Lyra the Harp

Lyra is close to the wing of Cygnus, a small constellation shaped like a diamond with a V on top. Another very old and well-observed constellation, Lyra, is recorded on Ptolemy’s 2nd-century list of ancient constellations. Lyra is nearly overhead shortly after midnight at the start of summer. Of the 5 main stars within this small constellation, one stands head and shoulders above all the others in terms of brightness and importance. Alpha Lyrae, or to give it its common name, Vega, is without doubt one of the prettiest stars in the Northern Hemisphere, and it has also been the focus of groundbreaking astronomical research, so much so, that at times it has been described as the next most important star in the sky after our Sun.



Vega is a blue-tinged white main-sequence star about 25 light years away from the Earth; it is middle-aged and still fusing hydrogen to helium in its core. It is about 1 and a half times the size of the Sun and, as a result, will have a shorter lifespan. It is the 5th brightest star in the night sky and the 2nd brightest in the Northern Hemisphere after Arcturus.

It has been studied for centuries, and Vega was the northern pole star around 12,000 BCE, a role it will take back from Polaris in around 11,500 years. After the Sun, Vega was the first star to have its image and spectrum photographed, and it was one of the first stars whose distance was estimated through parallax measurements. It truly is one of the key stars of modern astronomy.

Other notable features within the constellation of Lyra include the beautiful Ring Nebula or M57. It is a planetary emission nebula that was formed by the expulsion of gas from a dying star. The Nebula is relatively easy to find with a telescope as it lies approximately halfway between the two lower stars of the Lyra constellation.

Aquila the Eagle

Looking towards the East after dark in summer, you should easily spot the bright star in the constellation Aquila the Eagle. Another of the ancient constellations noted by Ptolemy in the 2nd century, the Eagle has been called different things in the past, including the Flying Vulture by the Romans. The bright star in the neck of the Eagle is Altair, and it is the 12th brightest star in the night sky, residing some 16 light years away from Earth.



Altair is a young whitish star which is still in the hydrogen-fusing stage of its life; like Vega, it is about 1.8 times the size of our Sun, but unlike our star, it is rotating at a very high speed, estimated to be about 1 revolution every 8 hours. This phenomenon means that the star is not spherical but rather oblate – as the sides are forced outwards, making the diameter of the equator at least 20 times bigger than the diameter between the poles.

Because of the constellation's location along the plane of the Milky Way, there are few galaxies within the constellation, but there are plenty of nebulae, including the Glowing Eye nebula (NGC6751) and the Snow Globe nebula (NGC6781).

The planetarium

The Moon
Here are the Moon’s phases during July, along with the dates.
• New Moon – 5th July 2024
• First Quarter – 13th July 2024
• Full Moon – 21st July 2024
• Last Quarter – 28th July 2024

July’s full moon is called the Full Thunder Moon, after the frequent thunderstorms that roll in during early summer.
Thanks to MoonGiant for this information; read more about the July Moon phases on their website.

Mercury
Mercury is starting to become easier to spot in the Western skies 30 minutes after sunset and will reach its greatest Eastern elongation from the Sun on 22nd July. A great evening to catch a glimpse of Mercury will be on July 7th, as a thin crescent moon will sit almost directly above it 20 minutes after sunset.

Venus
Venus is starting to escape the sun's glare, but it is still challenging to observe. It will set completely less than 30 minutes after sunset. I advise giving the planet of love a miss for this month while she continues her transition into an evening planet.

Mars
Mars will begin rising at about 2 a.m. at the start of the month, but its orbit will be challenging to observe due to its 1-magnitude brightness. Starting the month in Aries, it will transition into Taurus from July 12th. The best opportunity to spot Mars will be at the end of July when the planet will sit above the star Aldebaran in Taurus – very briefly; the Bull will have two red eyes rather than just one.

Jupiter
Jupiter’s is rising from about 3 am onwards and is becoming steadily brighter. You will struggle to miss him if you are up this early in the morning, as he will be the brightest object in the sky. If you still need help, look for the star cluster of the Pleiades and look south; the brightest object beneath the seven sisters will be Jupiter.

Saturn
Saturn rises at midnight on July 1, located in northeastern Aquarius. It should be easy to spot as it shines below 1 magnitude. Also, this is a great opportunity to see the gas giant side on through a telescope. Doing so, you shouldn’t be able to see any rings at all, and you could get a great view of Saturn's largest moon, Titan.


Next Month’s Preview
Next month I will look at how to spot the ISS and other manmade satellites from the comfort of your own back garden.

What did you think of this edition of UFP Stellar Cartography? Let us know in the comments below.

WRITTEN BY WoorLord
EDITED BY WoorLord
IMAGES SOURCED FROM MoonGiant.com - Other images sources from Stellarium.org.