Astroblog

To be read in conjunction with the astrophiz podcast #239

Evening Sky:

Venus climbs higher in the evening sky and is now in Virgo and well visible after the sky is fully dark. Venus is a distinct “Half Moon” phase in even small telescopes. On the 15th, Venus reaches its greatest elongation 46° east of the Sun. On the 15th, Venus, crescent Moon and Spica form a line in evening sky. On the 16th, Venus is less than 2°from the 4-day-old waxing crescent Moon, an impressive sight in the evening sky.

Saturn s is low in the late evening skies in August in Pisces Saturn rises around 10:30 pm at the start of the month in the eastern sky. By the end of the month, Saturn is rising at 8:30 pm ahead of its September opposition. Saturn is still best in the morning sky for most of August. 

Jupiter is lost in the twilight glow.

Morning sky:

Mercury returns to the morning skies but remains low in the twilight and difficult to see.  

Mars is above the eastern horizon at astronomical twilight in the morning. Mars in Gemini. On the 3rd the Red Planet passes with 1.5° of the Crab Nebula (M1), the famous supernova remnant (difficult in binoculars). Between the 14th and 17th, Mars is within 1° of the open cluster M35 (visible in binoculars). 

On the 9th the crescent Moon is near Mars very close to Elnath (Beta Tauri, occultation).  

Saturn Saturn is about 7° from the waning Moon on the 4th. 

August 6	Last Quarter Moon (ideal for star gazing)
August 10	Moon at apogee
August 13	New Moon (also ideal for star gazing total solar eclipse northern hemisphere)
August 20	First Quarter Moon (Lunar X moon in twilight on east coast)
August 22	Apogee Moon
July 30	Full Moon

The northern sky as seen at 23:00 ACST from Adelaide. The bright stars Altair, Deneb and Vega are seen forming the 'Winter triangle" in the northern sky.  Similar views will been seen elsewhere in Australia at the equivalent local time.	The winter triangle with the constellation names and lines added.

 

In August the Milky way passes across the Zenith in the early evening, making Scorpius, the scorpion, and Sagittarius the distinct Teapot asterism dominating the sky. Unfortunately that means you will get a crick in the Neck trying to watch them unless lying on the ground

This month we look to the northern skies and the constellation Aquila. The constellation is faint, and the most notable stars are the bright star Altair, flanked by two dimmer, but still bright stars. This grouping is instantly recognisable as there are no other bright stars close by. 
The name Aquila means eagle in Latin and in Greco-Roman mythology Aquila is the bird that carried Zeus’s (Jupiter's) thunderbolts.

The eagle motif of Aquila also appears in Indigenous astronomy. For the Koori people of Victoria, Altair represented Bunjil the Eaglehawk. The stars to each side of him were his two wives, a pair of black swans. To the Boorong people of western Victoria, Altair was Totyerguil, the son of Neilloan (the mallee fowl, represented by the star Vega), and the stars on either side were his two wives. Totyerguil may also represent an eagle.

While there are no thunderbolts for this celestial eagle, Aquila covers a nice swath of the Milky Way and a dust lane. Unfortunately there are no bright clusters or galaxies to enchant us, but if you sweep the area around Altair with binoculars under dark skies you will be rewarded with faint but delightful star clouds. In dark sky locations there is an “E” shaped dark nebula west of Altair that is easily visible in binoculars. 

Altair is also the vertex of the pattern of stars known as the Winter Triangle in the southern hemisphere (or the Summer Triangle in the northern hemisphere). This is made up of Altair itself, the bright star Vega which is close to the northern horizon and the bright star Deneb, which is even closer to the horizon (and may be difficult to see in southern Australia). This large triangle encloses a large section of the Milky.

The position of the Southern Cross and the pointers makes Omega Centauri, a magnificent globular cluster, easy to find in the evening as it forms the apex of a triangle with the Beta Crucis  and Beta Centauri forming the base.

Meteors: Perseids, August 12.

The famous Perseids are not readily observable from most of Australia. The radiant will be below the horizon for many southern observers. Observers in Darwin and Cape York may see some meteors looking north at around 3-4 am.. 

Labels: Astrophiz, Monthly sky

The eastern sky at 04:54 ACST Sunday, August 9, as seen from Adelaide. The Moon is about to finish occulting the bright star Elnath. The inset shows the telescopic view at the time. (click to embiggen).	The eastern sky at 04:34 AEST Sunday, August 9, as seen from Brisbane. The Moon is about to occult the bright star Elnath. The inset shows the telescopic view at the time. (click to embiggen).	The eastern sky at 04:41 AEST Sunday, August 9, as seen from Melbourne. The Moon is about to occult the bright star Elnath. The inset shows the telescopic view at the time. (click to embiggen).

An occultation of Elnath, (Beta Tauri) occurs in the early morning of Sunday August 9.
This is best seen from the east coast. For Mebourne and Hobart, the Moon occults Elnath when it is very low, so egress may be better for observation.Western Australia sees a close approach. The Moon is past last quarter low in the eastern sky for easy binocular/telescope observation, although telescope is best

Place	Disappears Bright Limb	Reappears Dark Limb
Adelaide ACST	-	4:54
Brisbane  AEST	04:34	5:35
Canberra AEST	04:42	05:27
Darwin ACST	04:00	04:26
Hobart AEST	05:04	05:14
Melbourne AEDST	04:41	05:24
Perth AWST	-	-
Sydney AEST	04:43	05:29

Labels: binocular, Moon, Occultation, telescope

The last Quarter Moon is Thursday August 6 and the New Moon is Thursday August 13. In the morning Saturn and Mars form a long line. Saturn is rising just around 10:30 pm local time. Mars is below the red star Aldebaran, pairing with Elnath (Beta Tauri). On the 9th the waning Moon occults Elnath and is near Mars. In the evening, Venus is visible well after the sky is fully dark . 

The last Quarter Moon is Thursday August 6 and the New Moon is Thursday August 13. The Moon at perigee, when it is closest to earth, on August 10.

North-Eastern horizon on the morning of Sunday, August 9 as seen from Adelaide at 5:41 ACST (90 minutes before sunrise, click to embiggen). 

Saturn is high above the north-western horizon.  Mars is low in the east, below the bright red star Aldebaran, forming a second tip to the horns of Taurus the Bull pairing with Elnath (Beta Tauri). 

The Moon is near Mars and will occult Elnath at roughly 4:30 am everywhere but WA. For detailed times see my Elnath occultation page.

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (90 minutes before sunrise). 

Western sky on the evening of  Saturday,  August 8  as seen from Adelaide at 19:05 ACST (90 minutes after sunset, click to embiggen). 

Venus is well above the horizon when the sky is fully dark. The inset is the telescopic view of Venus at this time. Venus is a clear "Half Moon"  shape and is increasing in size.  The shape is readily visible in even small telescopes (although the brightness may make it hard to see).

 

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset). 

Eastern horizon on the evening of Saturday, August 4 as seen from Adelaide at 23:30 ACST (click to embiggen). 

Saturn is the brightest object above the eastern horizon. Saturn is rising before midnight, but is still best for telescopic observation in the morning, and its rings are widening. 

The inset shows the telescopic view of Saturn at this time.    

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time. 

Labels: weekly sky

The Full Moon is Thursday July 30, the last Quarter Moon is Thursday August 6. In the morning Saturn and Mars form a long line. Saturn is rising just around 10:30 pm local time and is near the waning Moon on the 4th. Mars is below the red star Aldebaran, pairing with Elnath (Beta Tauri). In the evening, Venus is visible well after the sky is fully dark and draws away from the bright star Regulus. 

The Full Moon is Thursday July 30, the last Quarter Moon is Thursday August 6.

North-Eastern horizon on the morning of Tuesday, August 4 as seen from Adelaide at 5:41 ACST (90 minutes before sunrise, click to embiggen). 

Saturn is high above the northern horizon with the waning Moon nearby.  Mars is low in the east, below the bright red star Aldebaran, forming a second tip to the horns of Taurus the Bull pairing with Elnath (Beta Tauri). Saturn is rising before midnight, but is still best for telescopic observation in the morning, and its rings are widening. 

The inset shows the telescopic view of Saturn at this time.    

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (90 minutes before sunrise). 

Western sky on the evening of  Saturday,  August 1  as seen from Adelaide at 19:01 ACST (90 minutes after sunset, click to embiggen). 

Venus is well above the horizon when the sky is fully dark. The inset is the telescopic view of Venus at this time.

 

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset). 

Labels: weekly sky

The Full Moon is Thursday July 30. In the morning Saturn and Mars form a long line. Saturn is rising just around 11 pm local time. Mars is below the red star Aldebaran. In the evening, Venus is visible well after the sky is fully dark and draws away from the bright star Regulus. The Southern Delta-Aquarids meteor shower peaks on Sunday July the 30th but moonlight washes it out. 

The Full Moon is Thursday July 30.  The Moon is at apogee when it is furthest from Earth, on the 26th.

North-Eastern horizon on the morning of Saturday, July 25 as seen from Adelaide at 5:47 ACST (90 minutes before sunrise, click to embiggen). 

Saturn is high above the northern horizon with  Mars low in the east. Saturn is rising before midnight, but is still best for telescopic observation in the morning, and its rings are widening. 

Mars is below the bright red star Aldebaran.

The inset shows the telescopic view of Saturn at this time.    

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (90 minutes before sunrise). 

Western sky on the evening of  Saturday, July 25 as seen from Adelaide at 18:58 ACST (90 minutes after sunset, click to embiggen). 

Venus is well above the horizon when the sky is fully dark. The inset is the telescopic view of Venus at this time.

 

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset). 

Evening sky looking North from Adelaide at 3:00 am local time on July 30th in South Australia. The starburst marks the radiant  (the point where the meteors appear to originate from) of the Southern Delta Aquariids.  Similar views will be seen elsewhere at the equivalent local time (click to embiggen).

 

The Southern Delta-Aquarids meteor shower peaks on Sunday July the 30th. The number of meteors you will see depends on how high the radiant is above the horizon, and how dark your sky is. The ZHR for Southern Delta Aquariids is 25 meteors per hour. 

Sadly, this year the full Moon is on the 30th, so there will be lots of moonlight interference. so you will be flat out seeing any meteors. This shower is best seen from best seen from midnight to 3 am. 

Labels: weekly sky

The First Quarter Moon is Tuesday July 21. In the morning Saturn and Mars form a long line. Saturn is rising just before midnight. Mars is below the red star Aldebaran. In the evening, Venus forms a triangle with the crescent moon and the bright star Regulus on the 17th. The following night  the crescent moon, Venus and Regulus form a line.

The First Quarter Moon is Tuesday July 21.

North-Eastern horizon on the morning of Saturday, July 18 as seen from Adelaide at 5:53 ACST (90 minutes before sunrise, click to embiggen). 

Saturn is high above the northern horizon with  Mars low in the east. Saturn is now high enough for telescopic observation, and its rings are widening. 

Mars is below the bright red star Aldebaran.

The inset shows the telescopic view of Saturn at this time.    

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (90 minutes before sunrise). 

Western sky on the evening of Friday, July 17 as seen from Adelaide at 18:22 ACST (60 minutes after sunset, click to embiggen). 

The bright star Regulus, he crescent Moon, and Venus form a shallow triangle. The inset is the telescopic view of Venus at this time.

 

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset). 

Labels: weekly sky

The New Moon is Wednesday July 14. In the morning Saturn and Mars form a long line. Saturn is rising near midnight. Mars and Uranus are are drawing apart. On the 12th Mars is near the crescent moon, on the 13th, Mars is closest to the red star Aldebaran, forming a second eye for Taurus the Bull. In the evening, on the 9th Venus is just 1° from Leo’s brightest star, Regulus. Then Venus draws away from Regulus forming a line with the crescent moon by weeks end. 

The New Moon is Wednesday July 14. The moon is at perigee, when it is closest to the earth on, the 13th.

Eastern horizon on the morning of Saturday, July 11 as seen from Adelaide at 5:53 ACST (90 minutes before sunrise, click to embiggen). 

Saturn is high above the northern horizon with  Mars low in the east. The Pleiades are close to the crescent moon Moon. Saturn is now high enough for telescopic observation, and its rings are widening. 

Mars forms a second eye for Taurus the Bull with Aldebaran.

The insets shows the telescopic view of Saturn at this time and the binocular view of the Moon and Pleiades.    

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (90 minutes before sunrise). 

Eastern horizon on the morning of Sunday, July 12 as seen from Adelaide at 5:53 ACST (90 minutes before sunrise, click to embiggen). 

Mars is near the Moon and forms a second "eye' with the bright red star Aldebaran for Taurus the Bull.  

The inset shows the binocular view of Mars, Uranus and the Pleiades at this time.   

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (90 minutes before sunrise). 

Western sky on the evening of Thursday, July 9 as seen from Adelaide at 18:18 ACST (60 minutes after sunset, click to embiggen). 

Jupiter is coming close to the horizon. Venus is closest to the bright star Regulus (Alpha Leonis). 

 

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset).

Western sky on the evening of Thursday, July 16 as seen from Adelaide at 18:22 ACST (60 minutes after sunset, click to embiggen). 

The crescent Moon, the bright star Regulus and Venus form a line. The inset is the telescopic view of Venus at this time.

 

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset). 

Labels: weekly sky

To be read in conjunction with the astrophiz podcast #237

Stars:

July 8	Last Quarter Moon (ideal for star gazing)
July13	Moon at apogee
July14	New Moon (also ideal for star gazing)
July 21	First Quarter Moon
July 26	Apogee Moon
July 30	Full Moon

South-Eastern sky as seen from Adelaide at 18:51 ACST on July 15 (90 minutes after sunset, click to embiggen). Scorpius is high in the sky. The inset shows the binocular view of the "sting" in the scorpions tail, with Ptolemy’s cluster. Similar views will been seen elsewhere in Australia at the equivalent local time. (90 minutes after sunset)	Southern sky as seen from Adelaide at 18:51 ACST on July 15 (90 minutes after sunset, click to embiggen). The Southern Cross is at its highest. The inset shows the binocular view of the the Southern Pleiades around Theta θ Carina and the eta Carina nebula. Similar views will been seen elsewhere in Australia at the equivalent local time. (90 minutes after sunset)

 

Scorpius the scorpion, is well above the eastern horizon in the east when the sky is fully dark.  It is almost galaxy season, with Sagittarius, and the heart of the Milky way, rising.  By around 11 pm local time, Scorpius lies across the Zenth with Sagittarius and the heart of the galaxy beneath. 

The scorpion is an excellent binocular hunting ground now. Where the “sting of the tail begins to around is a star grouping dominated by zeta 1 and 2 Scorpii of the called the false comet, below the end of the sting is Ptolemy’s cluster and the Butterfly cluster, heading on westward towards the lid of the Teapot of Sagittarius in the Triffid nebula and then below that the Globular cluster M22. 

At around astronomical twilight (090 minutes after sunset when the sky is fully dark) the Southern Cross will almost be at its highest due south. To the right and a bit below alpha Crucis , almost half-way between the Southern cross and the false cross is theta carina, the brightest star in the Southern Pleiades. Just above that is the broad fuzzy patch that is the Carina Nebula, with variable star eta Carina (too dim to see) across this nebulosity is a dark band, the keyhole nebula best seen with binoculars or a small telescope. 

The position of the Southern Cross and the pointers makes Omega Centauri, a magnificent globular cluster, easy to find in the evening as it forms the apex of a triangle with the Beta Crucis  and Beta Centauri forming the base.

Meteors: Southern delta Aquariids:

The Southern Delta-Aquarids meteor shower runs from 12 July to 23rd August, peaking on Sunday July the 30th. The number of meteors you will see depends on how high the radiant is above the horizon, and how dark your sky is. The ZHR for Southern Delta Aquariids is 25 meteors per hour. 

In practice, you will never see these many meteors as the radiant will be some distance below the zenith. Also, unless you are out deep in the countryside, the darkness will be less than ideal. This shower is fairly faint, with the highest rate of around a meteor every 4-5 minutes. 

Sadly, this year the full Moon is on the 30th, so there will be lots of moonlight interference. This shower is best seen from best seen from midnight to 3 am. 

Labels: Astrophiz, Monthly sky