Astroblog

   

Western sky on the evening of  Wednesday,  September 2  as seen from Adelaide at 19:21ACST (90 minutes after sunset, click to embiggen).  Venus is well above the horizon when the sky is fully dark. has been coming closer to to the bright star Spica and is closest on the 2nd. Venus is a clear "Crescent 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  (90 minutes after sunset)	North-Eastern horizon on the morning of Monday, September 7 as seen from Adelaide at 5:03 ACST (90 minutes before sunrise, click to embiggen).  Saturn is above the north-western horizon.  Mars is low in the east.The Moon is near Mars.  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  Monday,  September 14  as seen from Adelaide at 19:01 ACST (60 minutes after sunset, click to embiggen).  Venus is well above the horizon when the sky is fully dark. It is close to the thin crescent Moon. Venus itself is a clear "Crescent Moon"  shape and is increasing in size.  The shape is readily visible in even small telescopes. Mercury is just peeping over the horizon. 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  Saturday,  September 26  as seen from Adelaide at 19:01 ACST (60 minutes after sunset, click to embiggen).  Mercury is Visible close to the bright Star Spica  at nautical twilight, below Venus.Venus is a  thinning "Crescent Moon" shape. Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset)

 Mercury enters the evening twilight late in the month. From the 16th it can be seen low above th western horizon, forming a line with Spica and Venus, On the 26th, Mercury will be less than a degree from 1st magnitude Spica, with Venus above.

Venus is now in Virgo. It begins to sink in the evening sky dut is still well visible after the sky is fully dark. Venus is a distinct “Crescent Moon” phase in even small telescopes. For the first couple of days, Venus will be less than 2°from Virgo’s brightest star, Spica. On the 14th, Venus is 2°from the 4-day-old waxing crescent Moon, an impressive sight in the evening sky. On the 19th, Venus is at its greatest brilliance at − 4.5 magnitude.

Saturn is rising higher ahead of opposition next month, when it is biggest and brightest as seen for earth.  At the beginning of the-month it is rising around 8:30 pm and is highest at 2:30 am. Mid-month it is rising around astronomical twilight and is highest around 1:30 pm. By the end of the Month, it is highest around midnight. On September 27th the full Moon is ~6° from Saturn. The rings are widening

Morning sky:

Mars is above the eastern horizon at astronomical twilight in the morning. Mars in Gemini. On the 7th, it is 4° south of the 25-dayold waning crescent Moon. 

Saturn is highest around 2pm to midnight as the month rolls on. While in a good viewing position in the evening, it is still best telescopically in the very early morning. 

Jupiter enters the morning sky and -is low above the horizon. On the 9th, the planet will be around 2° from the 27-day‑old waning crescent Moon, low above the horizon it the twilight. By the end of the month it is still low, but more readily seen.

First Quarter perigee moon at 21:58 ACDST on February 24. Actual First Quarter is 8:48 on the 25th and perigee is 21:58 (a 1 day 10 hour difference).	First Quarter apogee moon at 19:34 ACST on September 19, actual First Quarter is 07:19, apogee is 13:30 (an ~6 hour difference). The size difference between this and the Perigee First Quarter in February will be clear in telescopes.

 

Occultation of Antares, Tuesday September 17/18. (Approaching first Quarter)

The western sky at 23:37 ACST Tuesday, September 17, as seen from Adelaide. The Moon is about to occult the bright star Antares low on the horizon. The inset shows the telescopic view at the time. (click to embiggen).	The western sky at 00:0 AEST Wednesday, September 18, as seen from Canderra. The Moon is about to occult the bright star Antares low on the horizon. The inset shows the telescopic view at the time. (click to embiggen).	The western sky at 23:59 AEST Tuesday, September 17, as seen from Melbourne. The Moon is about to occult the bright star Antares low on the horizon. The inset shows the telescopic view at the time. (click to embiggen).

An occultation best seen from the east coast south of Sydney around midnight. The Moon is Approaching first Quarter and low above the horizon. Antares sets before it can reappear.

Place	Disappears Bright Limb	Reappears Dark Limb
Adelaide ACST	23:37	-
Brisbane  AEST	-	-
Canberra AEST (18th)	00:00	-
Darwin ACST	-	-
Hobart AEST	23:51	-
Melbourne AEDST	23:59	-
Perth AWST	-	-
Sydney AEST	-	-

Stars:

The northern sky as seen at 19:28 ACST from Adelaide on September 11 (90 minutes after sunset, New Moon). The bright stars Altair, Deneb and Vega are seen forming the 'Winter triangle" in the northern sky.  Sagittarius is at the Zenith and  the location of the globular cluster M22 is indicated by the box. The inset shows the telescopic view. Similar views will been seen elsewhere in Australia 90 minutes after sunset.

The Southern sky as seen at 19:28 ACST from Adelaide on September 11 (90 minutes after sunset, New Moon). The bright stars alpha and beta Centauri are readily visible with the Southern Cross below. The globular clusters 47 Tucana and Omega Centauri are  indicated. The inset shows the telescopic view of 47 Tucana. The small and large Magellanuic clouds are also seen. Similar views will been seen elsewhere in Australia 90 minutes after sunset.

 Scorpius the scorpion is now heading westwards.  Sagittarius, and the heart of the Milky way, is at the zenith from around 8 pm. This is an excellent time to observe the wealth of clusters in this area. The magnificent globular cluster M22 is at its highest that this time. It’s rival Omega Centauri is setting but still high and readily visible, and the other magnificent globular cluster 47 Tucana is rising. The three form a broad triangle across the Southern Sky. To the north the winter triangle of Deneb, Vega and Altair is clear

By mid month, the classic Andromeda galaxy is seen rising low above the northern horizon, while in the south the two dwarf galaxies, the Magellanic clouds, are rising too, with the SMC almost at its highest.

The southern cross is at about the 4 o'clock position, with the pointers above, just to the south of the pointers is the obviously triangular constellation of Triangulum Australae, the above that is Ara, the altar. These dim constellations are often overlooked but are interesting and have some nice small clusters in them. 

Meteors: No notable meteor showers this month.

Labels: Astrophiz, Monthly sky

# posted by Ian Musgrave @ 6:03 pm 0 comments

   

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).	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 below.  Similar views will be seen from the rest of Australia at roughly the equivalent local time  (90 minutes before sunrise) .
North-Eastern horizon on the morning of Saturday, August 15 as seen from Adelaide at 5:31 ACST (90 minutes before sunrise, click to embiggen). Mars is at its closest to the open cluster M35. The inset is the binocular view of Mars and the cluster. 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 Sunday, August 16 as seen from Adelaide at 19:19 ACST (90 minutes after sunset, click to embiggen). Venus, and the thin crescent Moon are close together, with the bright star Spica above. The inset shows 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:

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. 

First Quarter Moon at 17:00 ACST (06:30 UT) on August 20 as seen from Adelaide. The moon is in twilight, but the lunar X is still visible.The inset shows the Lunar X (top) and Lunar V (bottom),

Occultation of Elnath, 9 August, 2026

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

Stars:

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

# posted by Ian Musgrave @ 11:28 pm 0 comments

   

Eastern horizon on the morning of Saturday, July 4 as seen from Adelaide at 5:54 ACST (90 minutes before sunrise, click to embiggen).Mars is closest to Uranus and between the Hyades and Pleiades clusters. 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).	Eastern horizon on the morning of Wednesday, July 8 as seen from Adelaide at 5:54 ACST (90 minutes before sunrise, click to embiggen). Saturn and Mars form a long line in the twilight. Saturn is close to the waning Moon. Saturn is now high enough for telescopic observation, and its rings are widening. Mars is in between Pleiades and Hyades and forms a second eye for Taurus the Bull with Aldebaran.The inset shows the telescopic view of Saturn at this time. Similar views will be seen from the r est 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 Friday, July 17 as seen from Adelaide at 18:22 ACST (60 minutes after sunset, click to embiggen). Venus, the thin crescent Moon and  the bright star Regulus (Alpha Leonis) form a line. Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset).

Stars:

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

# posted by Ian Musgrave @ 12:23 am 0 comments

To be read in conjunction with the "Tangent" section of the astrophiz podcast #235
https://soundcloud.com/astrophiz/astrophiz-235-june-2026-sky-guide

 There is a video going around on that wretched hive of villainy and scum called twitter labelled “Comets are not what we’ve been told”.  It shows some very nice time lapses of bright comets with the caption ‘Watch how it moves in lockstep with the stars” …. And that’s it. That’s the argument. 

Now, many people think because bright comets with the luminous tails look “swooshy” they must move perceptibly, like meteors. So perhaps the the lack of perceptible movement meant the comets were something else due to their naive expectations .... hence the earth is flat for .. reasons.  But comets are exactly what we have been told (and the earth is not flat).

In a single night, when viewed from afar, most comets will not seem to move against the background stars, especially as the time window before they set is short. But through a telescope (or telescopic lens) you can see them move a bit. For C/2024 G3 and C/2025 R3 I had a roughly 20 minute window for imaging, so I wasn’t going to see much motion, but for C/20025 R3 I could compare my images with those by other astrophotographers in the Southern Hemisphere, and see for example, images taken a few hours previous in New Zealand showed the comet had move compared to my images.

And night after night they are against different stars as the follow their orbit. Comet C/2025 R3 was particularly lovely, not bright but drifting past the sword of Orion’s belt each night was memorable.  

Comet C/2025R3 and Orion on the 10th May. Can't really see the tail against the light pollution. My image, long exposure (left) vs stellarium.	Comet C/2025R3 and Orion on the 10th May as simulated in stellarium.. Compare with my image, long exposure on the right.

Comet C/2025R3 and Orion on the 11th May. Sort of got a stubby tail against the light pollution. My image, long exposure (left) vs stellarium.	Comet C/2025R3 and Orion on the 11th May as simulated in stellarium.. Compare with my image, long exposure on the right.

Comet C/2025 R3, at the time it was crossing Orion’s belt, was moving around 1 degree every 24 hours, slow compared to the moon, which moves ~13.2 degrees every 24 hours, but not too different from the movement Venus, which moves on Average ~1.2 degrees per day and fleet Mercury which moves on average ~1.3833 degrees per day (0.5 degrees is roughly the diameter of the moon, which moves approximately one lunar diameter per hour). Mars moves ~ 0.5242 degrees per day and Jupiter, Saturn and the rest much less. This is why Jupiter and Saturn seem to stay in roughly the same place night after night. This is complicated by retrograde motion, where earth overtakes the planets in their orbits. 

Mercury and Venus have a narrow window before they set to see them move in a single night. On the 20th and 21st you have about a 2 hour window to see Venus move against the background stars of the Beehive cluster, you do need a flat level horizon for this. (of course, day to day they move quite a bit with close approaches to other planets and stars over a matter of days).  

Western sky on the evening of Saturday, June 20 as seen from Adelaide at 18:11 ACST (60 minutes after sunset, click to embiggen).  Venus is at its closest to the Beehive Cluster (M44).	Binocular view Venus and the Beehive at 18:11 ACST	Binocular view Venus and the Beehive at 19:41 ACST. Venus has slightly, but perceptibly moved against the stars of the Beehive.

We tend not to notice the relatively rapid movement on the Moon during the night, not may people are out looking at the sky for hours on end. Only when the moon is close to a very bright star do we sometime take notice. 

On the 23rd you can follow the waxing Moon as it comes closer to the bright star Spica, in binoculars you will be able to see it come close to the star 49 Virginis over the span of a few hours. Of course on the 28th, in the early Morning you can watch the moon occult (or graze) Antares. 

The Moon at the evening of Tuesday, June 21 as seen from Adelaide at 18:12 ACST (60 minutes after sunset, click to embiggen). The Moon is close to the bright star Spica	The Moon as seen through binoculars  at 18:12 ACST (60 minutes after sunset, click to embiggen). The Moon is near the star 49 Virginis	The Moon as seen through binoculars  at 22:00 ACST. The Moon is now beside the star 49 Virginis and visibly closer to Spica.

Labels: Astrophiz, comet, Moon.

# posted by Ian Musgrave @ 11:58 pm 0 comments

 

Western sky on the evening of Wednesday, June  8 as seen from Adelaide at 18:11 ACST (60 minutes after sunset, click to embiggen). Venus Jupiter, Pollux and Castor form a battered line, with Mercury below, very close to epsilon Geminorum.  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, June 17 as seen from Adelaide at 18:11 ACST (60 minutes after sunset, click to embiggen).  Mercury, Jupiter and the thin crescent Moon form a triangle, as does Jupiter Venus and the Moon. 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 Wednesday, June 24 as seen from Adelaide at 18:12 ACST (60 minutes after sunset, click to embiggen).  Mercury is at its greatest elongation from the Sun. Mercury, Jupiter and Venus and the Moon form a line. Similar views will be seen from the rest of Australia at roughly the equivalent local time  (60 minutes after sunset).	Eastern morning sky on Tuesday, June 30 as seen from Adelaide at 5:54 ACST (90 minutes before sunrise, click to embiggen).  Mars is within binocular distance of the Pleiades (brackets) and Uranus. Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes before sunrise)

Dates and time Lunar X and V are visible. Typically visible from about 4hours from the starting time.

First Quarter Moon at 20:11 ACST (9:41 UT) on June 22. The inset shows the Lunar X (top) and Lunar V (bottom), 

The First Quarter Moon is clearly visible high above the north-western horizon forming. The Lunar X and V may be seen in a telescope or strong binoculars. The image shows the telescopic view at this time. 

 

 

 

 

 

 

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

 

 Occultation of Antares 28 June: 

The western sky at 02:22 AEST Sunday, June 28, as seen from Canberra. The Moon is about to occult the bright star Antares. The inset shows the telescopic view at the time. (click to embiggen). Click to embiggen	The western sky at 02:27 AEST Sunday, June 28, as seen from Sydney. The Moon is about to occult the bright star Antares. The inset shows the telescopic view at the time. (click to embiggen). Click to embiggen	The western sky at 02:12 AEST Sunday, June 28, as seen from Melbourne. The moon is about to occult the bright star Antares. The inset shows the telescopic view at the time. (click to embiggen). Click to embiggen

An early morning occultation best seen from the east coast south of the Gold Coast (which sees a graze). Everywhere else in Australia sees a close approach. The Moon is two days of full and sufficiently high in the sky for easy binocular/telescope observation, although telescope is best.

Place	Disappears dark Limb	Reappears Bright Limb
Adelaide ACST	-	-
Brisbane  AEST	-	-
Canberra AEST	02:22	03:01
Darwin ACST	-	-
Hobart AEST	01:58	03:01
Melbourne AEDST	02:12	02:57
Perth AWST	-	-
Sydney AEST	02:27	03:03

Stars:

South-Eastern sky as seen from Adelaide at 18:48 ACST on June 15 (90 minutes after sunset, click to embiggen). The dark constellation of the Emu is prominent. Scorpius form the fringe of feathes on the  Emus body. Similar views will been seen elsewhere in Australia at the equivalent local time. (90 minutes after sunset)	Southern sky as seen from Adelaide at 20:20 ACST on June 15 . The Southern Cross is at its highest, and the magnificent globular cluster Omega Centauri (indicated by brackets) is also at its highest. Similar views will been seen elsewhere in Australia at the equivalent local time. (click to embiggen)

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 midnight, Scorpius lies across the Zenith with Sagittarius and the heart of the galaxy beneath. Now is a good time to see the dark constellation of the Emu rising in the sky shortly after astronomical twilight. The appearance of the Emu in June tells the people to stop collecting emu eggs for food.

At 8 pm local time, the southern cross is at its highest, and the magnificent globular cluster Omega Centauri is also at its highest. The globular cluster 47 Tucana is at its lowest almost due south.  The False cross, the southern Pleiades and the riot of clusters around eta Carina are also prominent.

Labels: Astrophiz, Monthly sky

# posted by Ian Musgrave @ 11:42 pm 0 comments

Printable Black and White chart for locating Comet 12P 10April-10 May. Click to embiggen and print. Use with a red light torch (or a standard torch with red cellophane over it) to preserve your night vision.	Printable Black and White Binocular chart for locating Comet 12P. The circle represents the approximate field of view of 10x50 binoculars.Click to embiggen and print. Use with a red light torch (or a standard torch with red cellophane over it) to preserve your night vision.
Photo realistic view of the evening sky simulated in Stellarium for Sunday, April 14 as seen from Adelaide at 18:48 ACST (60 minutes after sunset, click to embiggen). Jupiter is very low above the north-western horizon and within binocular distance of Uranus and the comet 12P (the inset is the approximate binocular view of the trio).	Photo realistic view of the evening sky on Sunday, April 21 as seen from Adelaide at 18:39 ACST (60 minutes after sunset, click to embiggen). Jupiter is almost lost above the north-western horizon. Comet 12P is close to the pair of Xi and omicron Tau (the inset is the approximate binocular view of the trio).

While the comet is a reasonably bright magnitude 4.5, about as bright as the star Taygeta (19 Tau) in the Pleiades, it is so low to the horizon that you will be difficult to see it through the horizon murk over the next week or so. You will definitely need binoculars, even if you can see the brighter stars of the nearby Pleiades clearly. While the comet is much brighter than Vesta in the Vesta challenge, it is lower in the horizon murk and a more extended object, making it more of a challenge.

On the 14th  the comet will be within binocular distance of Jupiter. Although the comet is magnitude 4.5 at this time and theoretically dimly visible to the unaided eye, atmospheric extinction will mean it is more like magnitude 6. The comet will look like a faint fuzzy dot.

At nautical twilight (an hour after sunset) it will be around three finger-widths above the horizon (and you will need a level, unobstructed horizon to see it). You may have better success looking a bit earlier, when it will be higher despite the brighter twilight sky. Terry Lovejoy was successful in capturing the comet with 7x 1 second exposures at 100 ASA using a Sony A7iii.

Using a more ordinary camera, try zooming in around 3x and using mutiple1 second 100 ISO imaging (you WILL need a tripod for this). Higher ISO (ASA) values will make the sky brighter as well as the comet, so will not be as effective. You may wish to play around with the settings if you have time before the comet sets. 

UPDATE: forget everything I said about imaging. I have been able to get it with 1 second ISO 3200 and 3x zoom, but nothing below ISO 1600. (I have also done 2 and 4 second exposures, but I have an S24, so that’s cheating). I have yet to try stacking, there may be too few stars visible to stack reliably. 

12P Pons-Brooks will climb higher and brighten as it rises (not much though). It should be more or less easily located in binoculars by sweeping up from Jupiter (see printable charts and maps above).

On the 21st the comet will be at it's brightest (unless it undergoes another outburst, it has had nights where it was substantially brighter) at magnitude 4.4 (although atmospheric extinction means it is more like magnitude 5.3 at astronomical twilight, an hour after sunset). At this time it will be nearly two hand-spans above the horizon, almost on top of the two stars Xi and omicron Tau (both around magnitude 3 and readily visible, see charts above). If you can't readily see the pair locate the rather obvious Aldebaran (and the Hyades) and sweep down an to the west by about three binocular widths and the pair should be obvious.

Again, you may wish to look earlier when the comet is higher, and the twilight brighter. While the comet will still look like a fuzzy dot in binoculars, you may be able to see a short tail. 

For imaging try zooming in so the pair of Xi and omicron Tau take up a decent proportion of the field of view (not too  much as the resolution of most point and click cameras and mobile phones degrade severely on zoom) and take multiple 1 second images (I use between 10-20 images), you may try higher ISOs to try and capture more comet detail. Stack the images with an appropriate stacking software. Free Stacking software includes Deep Sky Stacker and Autostakkert for Windows,  and StarStaX for macOS. 

After this 12P Pons-Brooks begins to fade, but still remains "bright", sweeping your binoculars up from Xi and omicron Tau should pick it up. on the 29th it is within binocular distance of nu Tau (see charts, sweep west of Aldebaran for around two binocular widths). At this time, at nautical twilight is over two hand-spans from the horizon and magnitude 4.5 and another good opportunity for imaging.

Labels: 12P, Astrophiz, astrophotography, comet

# posted by Ian Musgrave @ 5:42 pm 0 comments