August 2019

As the month begins, the Sun is passing through the stars of Cancer, until around 06h on the 11th, when it crosses the boundary into Leo, where it remains for the rest of the month. From the beginning of the month, truly dark nights begin again in northern UK.

The Moon

The Moon is at perigee, its nearest to the earth, at 07h on the 2^nd (33 minutes of arc diameter), and there is a second perigee is on the 30^th at 16h00. It is at apogee (furthest from the earth) at 11h00 on the 17^th (30 minutes of arc)

New Moon is on the 1^st at 03h12 in the constellation of Cancer, just to the north of the Sun, when it passes about 1° above the Sun.

A second New Moon occurs on the 30^th at 10h38 in Leo, when the Moon passes 3° north of the Sun. Some people call the second New Moon in a month a ‘Black Moon’.

First Quarter Moon at 17h32 on the 7^th takes place in the constellation of Libra, 3° north of Zubenelgenubi (alpha Librae).

Full Moon occurs at 12h30 on the 15^th on the Capricornus/Aquarius border. Some would consider this to be the Harvest Moon as it more closely is at the time of the grain harvest in the northern hemisphere; however the title is now given to the September Full Moon and will be described next month.

Last Quarter Moon is on the 23^rd at 14h57 in the constellation of Taurus. 

It may be possible to glimpse earthshine on the night hemisphere of the waxing crescent Moon from the 2^nd to the 5^th, (although twilight and the Moon’s low altitude may interfere somewhat), and on the waning crescent Moon from the 24^th to the 29^th.

The Planets

Mercury is at greatest elongation west of the Sun (19°) on the 10^th, when around this time it rises at around 03h - about 2 hours before the Sun.

Use binoculars and scan the north-eastern horizon to find this bright (magnitude -0.08), yet elusive, little world. When using binoculars, only use them when the Sun is below the horizon: so that you do not, inadvertently catch the Sun in the binocular field of view, which will almost certainly result in permanent eye damage

Venus is at superior conjunction on the 14^th, and lies far beyond the Sun. It is therefore invisible to the unaided eye during the entire month. After the 14^th, theoretically it becomes ‘Hesperus’, the ‘Evening Star’ of the Ancients.

Mars is too near the Sun to be observed throughout the whole of August; its solar conjunction being at the beginning of September.

Jupiter is the most conspicuous object in the evening sky, with the exception of the Moon if present. It shines at visual magnitude -2.3, in the constellation of Ophiuchus, some 6° to the northeast of Antares, the red ‘heart’ of the Scorpion. By the end of the month, Jupiter sets at 22h. On the 9^th in the late evening, there is a lovely conjunction of the gibbous waxing Moon with bright Jupiter. At this time, Jupiter is 1.5° to the lower left of the waxing Moon, low in the south western sky.

Continue to observe the ever-changing positions of the Galilean moons through well focussed and firmly fixed binoculars, the daily configuration of which is on the front page of these Sky Notes.

Saturn continues to be within the constellation of Sagittarius the Archer, and embedded in the Milky Way. As a result, Saturn never gains a high altitude above the southern horizon from the latitude of the UK. The ‘ringed planet’ shining at magnitude +0.2, is visible as soon as it gets dark until the early hours of the morning. On the 11^th the waxing gibbous Moon may be seen approaching Saturn, the planet lying some 6° to the upper left of the Moon in the SSW sky, some 12° above the horizon.

The northern surface of the rings is still well presented towards the earth and so should delight observers with small telescopes on glimpsing this gem of the solar system.

Uranus, still in the southern reaches of the constellation of Aries, 10° to the south of Hamal (alpha Arietis) rises mid-evening during August. It lies on the threshold of naked eye visibility, but is readily visible in binoculars if you know where to look for it. There is a location chart available

on the ‘Remote Planets’ page in the MENU of these Sky Notes.

Neptune, three times fainter than Uranus, lies in the constellation of Aquarius, 40 mins of arc to the east of the

+4.3 magnitude star phi Aquarii.

Greater details of the planet’s position is to be found on the ‘Remote Planets’ page, accessible via the MENU.

One of the best shooting star showers of the year peaks at 07h on the 13^th, so is best seen during the early hours of the morning onthe 13^th. These meteors are called the Perseids, or the ‘Tears of St Lawrence’. Expect to see 80 or more shooting stars each hour, and especially in the early morning sky. Seeing conditions are unfavourable this year due to the presence of the Moon which is almost Full. However, if you turn your back on the setting Moon, you should still be able to see a grand ‘show’.

This is a rich shower of fast meteors, some of which will leave persistent trails. The Perseid meteors are associated with the Swift-Tuttle comet discovered in the nineteenth century. The period of this comet is 133 years and its next close approach to the earth will take place on August 5^th 2126. The current predicted distance between the comet and the earth on that occasion is 22,900,000 km (14,200,000 miles). Expect an exceptional shower in August of that year!!

There is more information on a dedicated page accessed via the MENU.

Constellations visible in the south around midnight, mid-month, are as follows: Capricornus, Aquarius, Equuleus (the Little Horse), Delphinus (The Dolphin) and Cygnus. The Milky Way is at the zenith, and spans the sky from the NE to the SW.

 SUMMARY

All times are GMT     1° is one finger width at arm’s length.

The phenomena of the month : August 2019
Times are given in UT for SCARBOROUGH (0° 25' 0" W, 54° 16' 3" N, zone Z).

Date Hour Description of the phenomenon
yyyy mm dd hh:mm

2019 08 01 03:12 NEW MOON
2019 08 02 07:08 Moon at perigee (geocentric dist. = 359398 km)
2019 08 02 17:45 Maximum of the variable star eta Aquilae
2019 08 03 18:37 Minimum of the variable star Algol (beta Persei)
2019 08 04 02:21 Maximum of the variable star delta Cephei
2019 08 06 15:26 Minimum of the variable star Algol (beta Persei)
2019 08 07 14:18 Opposition of the asteroid 16 Psyche with the Sun (dist. to the Sun = 2.708 AU; magn. = 9.3)
2019 08 07 17:31 FIRST QUARTER OF THE MOON
2019 08 08 09:00 Venus at its perihelion (distance to the Sun = 0.71846 AU)
2019 08 09 11:08 Maximum of the variable star delta Cephei
2019 08 09 12:15 Minimum of the variable star Algol (beta Persei)
2019 08 09 21:59 Maximum of the variable star eta Aquilae
2019 08 10 06:00 GREATEST WESTERN ELONGATION of Mercury (19.0°)
2019 08 10 08:14 Maximum of the variable star zeta Gemini
2019 08 11 21:47 Close encounter between the Moon and M 22 (topocentric dist. centre to centre = 0.6°)
2019 08 12 09:03 Minimum of the variable star Algol (beta Persei)
2019 08 12 22:28 Close encounter between the Moon and Pluto (topocentric dist. centre to centre = 0.8°)
2019 08 13 03:40 Meteor shower : Perseids (110 meteors/hour at zenith; duration = 38.0 days)
2019 08 13 06:27 Minimum of the variable star beta Lyrae
2019 08 13 15:16 Opposition of the asteroid 15 Eunomia with the Sun (dist. to the Sun = 2.400 AU; magn. = 8.2)
2019 08 14 06:04 SUPERIOR CONJUNCTION of Venus with the Sun (geoc. dist. centre to centre = 1.3°)
2019 08 14 19:55 Maximum of the variable star delta Cephei
2019 08 15 05:52 Minimum of the variable star Algol (beta Persei)
2019 08 15 12:29 FULL MOON
2019 08 17 02:14 Maximum of the variable star eta Aquilae
2019 08 17 05:59 Close encounter between Mercury and M 44 (topocentric dist. centre to centre = 1.2°)
2019 08 17 10:50 Moon at apogee (geocentric dist. = 406244 km)
2019 08 17 12:06 Opposition of the asteroid 39 Laetitia with the Sun (dist. to the Sun = 2.522 AU; magn. = 9.1)
2019 08 18 02:40 Minimum of the variable star Algol (beta Persei)
2019 08 18 07:01 Meteor shower : Kappa Cygnids (3 meteors/hour at zenith; duration = 22.0 days)
2019 08 20 04:42 Maximum of the variable star delta Cephei
2019 08 20 07:00 Mercury at its perihelion (distance to the Sun = 0.30750 AU)
2019 08 20 11:49 Maximum of the variable star zeta Gemini
2019 08 20 23:29 Minimum of the variable star Algol (beta Persei)
2019 08 23 14:56 LAST QUARTER OF THE MOON
2019 08 23 20:17 Minimum of the variable star Algol (beta Persei)
2019 08 24 02:48 Beginning of occultation of 61-delta1 Tau (magn. = 3.77)
2019 08 24 03:27 Beginning of occultation of 64-delta2 Tau (magn. = 4.80)
2019 08 24 03:57 End of occultation of 61-delta1 Tau (magn. = 3.77)
2019 08 24 06:29 Maximum of the variable star eta Aquilae
2019 08 25 06:00 VENUS at maximum brightness (magn. -3.93)
2019 08 25 13:29 Maximum of the variable star delta Cephei
2019 08 26 01:00 Mars at its aphelion (distance to the Sun = 1.66606 AU)
2019 08 26 05:02 Minimum of the variable star beta Lyrae
2019 08 26 17:06 Minimum of the variable star Algol (beta Persei)
2019 08 29 13:54 Minimum of the variable star Algol (beta Persei)
2019 08 30 10:37 NEW MOON
2019 08 30 15:24 Maximum of the variable star zeta Gemini
2019 08 30 15:57 Moon at perigee (geocentric dist. = 357176 km)
2019 08 30 19:22 Comet P/1999 R1 SOHO at its perihelion (dist. to the Sun = 0.052 AU; magn. = 7.7)
2019 08 30 20:19 Comet 322P SOHO at its perihelion (dist. to the Sun = 0.052 AU; magn. = 6.1)
2019 08 30 22:16 Maximum of the variable star delta Cephei
2019 08 31 10:43 Maximum of the variable star eta Aquilae

(Using Coelix Software)