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What’s up? Night sky for November 2011

People looking at the evening sky

Late spring nights and mornings are ideal for stargazing, and there are some interesting things to see this month.

Except where indicated, all of the phenomena described here can be seen with the unaided eye. And unless otherwise specified, dates and times are for the Australian Eastern Standard Time zone, and sky directions are from the point of view of an observer in the Southern Hemisphere.

November 3

It is First Quarter Moon today at 3:38am Australian Eastern Daylight Time. First Quarter is a good time to look at the Moon through a telescope, as the sunlight angle means the craters and mountains are throwing nice shadows, making it easier to get that 3D effect.

November 9

Take a look in the evening sky and you’ll see the Moon with what looks like a bright star above and to its right. Well, that’s not a star, it’s the planet Jupiter. Also today, the Moon will reach the farthest point from Earth in its orbit, apogee, at a distance from Earth of 406,176 kilometres.

November 10

Take a look at the western horizon after sunset and you’ll see a pretty group comprising Venus, Mercury and the star Antares.

Looking at the Moon with a telescope

The Moon teams up with several planets during November

November 11

Full Moon occurs today at 7:16am Australian Eastern Daylight Time.

November 11-12

Out to the east in the early morning sky (pre-dawn) you’ll find a pair of celestial orbs that contrast each other nicely in colour. Ruddy coloured Mars will appear very close to Regulus, a blue giant star that is the brightest star in the constellation Leo.

November 19

It is Last Quarter Moon today at 2:09am Australian Eastern Daylight Time. If you’re up before dawn, take a look out to the eastern sky and you’ll see the Moon with the star Regulus close by, and the planet Mars about 4 degrees away as well.

November 23

Another attractive grouping, but quite low in the eastern sky before dawn (so you’ll need a clear horizon). There’ll be the Moon, plus the star Spica (the brightest star in the constellation Virgo) and the planet Saturn as well.

November 24

Today the Moon will be at the closest point to Earth in its orbit, called perigee, which is the opposite of apogee. The distance between the two bodies today will be 359,691 kilometres.

November 25

New Moon occurs today at 5:10pm Australian Eastern Daylight Time.

November 27

Take a look out to the west just after sunset, and you might see the very thin crescent Moon below and to the right of the planet Venus.

If you have any questions or comments on the night sky, we’d be happy to answer them. Please use the Feedback Form below. Happy stargazing!

Images courtesy IAU / TWAN / Babak /A. Tafreshi.

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What’s up? Night sky for August 2011

Stargazers with telescopes

This month, Saturn will be the planet to watch in the western part of the sky after sunset.

FOUR PLANETS ARE VISIBLE THIS MONTH, although you’ll have to be quick to spot Mercury, as it starts the month low on the western horizon after sunset and within about a week will have become lost in the Sun’s glare.

Slightly higher in the western sky after sunset is Saturn, shining brightly and visited by the Moon on the 4th.

Jupiter and Mars are still the luminaries of the morning sky—Jupiter high in the north, and Mars low in the north-east. Their brighter sibling, Venus, will not be visible this month, as it is on the opposite side of the Sun from us.

Except where indicated, all of the phenomena described here can be seen with the unaided eye. And unless otherwise specified, dates and times are for the Australian Eastern Standard Time zone, and sky directions are from the point of view of an observer in the Southern Hemisphere.

August 1

Look for the very thin crescent Moon low in the west after sunset. The planet Mercury will be about seven Moon widths above and to the right. Mercury is becoming much harder to see now, and over the next week will sink lower and lower toward the horizon and become lost in the Sun’s glare. The innermost planet will reappear in our morning sky out to the east next month.

August 3

Today the Moon will be at the closest point to Earth in its orbit, called perigee, at 7:00am. The distance between the two bodies will be 365,755 kilometres.

August 4

Look for the Moon and Saturn close together in the west in the early evening sky.

August 5

The Moon and the star Spica—the brightest star in the constellation Virgo—will appear close together tonight. The Moon will be about six Moon widths above the star.

August 6

It is First Quarter Moon today at 9:08pm. First Quarter is a good time to look at the Moon through a telescope, as the sunlight angle means the craters and mountains throw nice shadows, making it easier to get that 3D effect.

August 8

Now almost three-quarters full, the Moon will be near the star Antares—the brightest star in the constellation Scorpius. Antares has a reddish colour, and to the naked eye it looks a bit like the planet Mars. In fact, its name means ‘rival of Mars’.

Stargazers

Make the most of the late-winter nights by doing some stargazing.

August 14

Full Moon will occur today at 4:58am.

August 16

If you’ve been wondering why Venus doesn’t appear to be in our evening or morning skies, it’s because it is lost in the glare of the Sun. Today marks its ‘superior conjunction’, which means that it is on the exact opposite side of the Sun from us.

August 17

Mercury, which has been lost in the glare of the setting Sun for a while now, today reaches ‘inferior conjunction’, which means that it is exactly between us and the Sun. Mercury will reappear low in the east in the morning sky next month.

August 19

Today the Moon will be at the farthest point from Earth in its orbit, called apogee, at 2:24am. The distance between the two bodies will be 405,159 kilometres.

August 21

Look out to the east this morning, and you’ll see the Moon and what looks like a very bright star above and to its left. That’s not a star; it’s the planet Jupiter. Even if you don’t have a telescope, a normal pair of binoculars should reveal up to four of Jupiter’s largest moons, looking like small pinpricks of light to one or both sides of the planets.

August 22

It is Last Quarter Moon today at 9:55pm.

August 26

If you’re an early riser, take a look out to the east and you’ll see the Moon very close to the planet Mars.

August 29

New Moon occurs today at 1:04pm.

August 31

Today the Moon will again be at the closest point to Earth in its orbit, perigee, this time at 3:36am. The distance between the two bodies will be 360,857 kilometres.

If you have any questions or comments on the night sky, we’d be happy to answer them. Please use the Feedback Form below. Happy stargazing!

Images courtesy IAU.

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What’s up? Night sky for July 2011

Telescope inside a dome at night

Stargazing during winter is chilly, but the nights can often be crisp and clear. And there's plenty to see this month!

THE INNERMOST PLANET, Mercury, has delighted us in the morning sky for the past couple of months, but this month it makes a reappearance in our evening skies, in the west after sunset. It’ll be quite easy to see, above the horizon for around 100 minutes after the Sun sets at the beginning of the month, increasing to almost two-and-a-half hours after the Sun sets by the end of the month.

Also in the evening sky, to the north-west, is Saturn. The famous ringed planet will be on show during the first half of the night, setting around 11:00pm by the end of the month.

In the morning sky to the east, Jupiter and Mars are still putting on a show before sunrise.

Venus is too close to the Sun to be seen this month.

Except where indicated, all of the phenomena described here can be seen with the unaided eye. And unless otherwise specified, dates and times are for the Australian Eastern Standard Time zone, and sky directions are from the point of view of an observer in the Southern Hemisphere.

July 1

There will be a partial eclipse of the Sun today, but you’ll have to be an albatross or maybe a seal in order to see it. That’s because the Sun’s shadow will fall across a remote area of ocean between South Africa and Antarctica. Unless there are some fishing boats or a scientific expedition in the area, it’s entirely possible that no one will witness this eclipse which, at its maximum, will see less than 10% of the Sun’s disc covered by the Moon. And speaking of the Moon, New Moon occurs today at 6:54pm Sydney time (08:54 Universal Time).

 

View of the night sky for July 3, 2011

July 3, 2011, 5:15pm: The thin crescent Moon will sit just above the planet Mercury in the western sky after sunset.

 

July 3

Take a look out to the west after sunset, and you should see the planet Mercury above the horizon, and above it will be the thin crescent Moon.

July 5

Earth reaches aphelion today (or July 4 in the western hemisphere), which is the farthest point from the Sun in our orbit. The distance between Earth and Sun will be 152.1 million kilometres.

There’ll be an interesting sight out to the east in the morning sky today. The planet Mars will appear close to the star Aldebaran. Both are of similar brightness, and both have similar colouring—a sort of orangey-red.

In this evening’s sky, the Moon will sit above the bright star Regulus. Regulus is the brightest star in the constellation Leo. The amazing thing about Regulus is that, although to the naked eye it appears to be one star, in reality it is composed of four stars grouped into two pairs, all gravitationally bound to each other! This sort of thing is not too uncommon—many other stars are members of double, triple or quadruple systems too.

Position of the Moon, Spica and Saturn on July 8, 2011

July 8, 2011, 7:15pm: The Moon will be bracketed by the planet Saturn and the star Spica, in the north-western sky.

 

 

July 8

It is First Quarter Moon today at 4:29pm Sydney time (06:29 Universal Time). First Quarter is a good time to look at the Moon through a telescope, as the sunlight angle means the craters and mountains throw nice shadows, making it easier to get that 3D effect. Also today, the Moon will be at the closest point to Earth in its orbit, called perigee, at 12:05am (14:05 on July 7, Universal Time). The distance between the two bodies will be 369,565 kilometres. And finally, tonight the Moon will appear reasonably near the planet Saturn.

July 9

A little more than half full, the Moon will appear quite close to the star Spica tonight. Spica, a blue giant star, is the brightest star in the constellation Virgo and the 15th-brightest star in our night sky.

Position of the Moon and Antares on July 12, 2011

July 12, 2011, 8:00pm: High in the northern sky, the Moon and the star Antares (the brightest star in the constellation Scorpius) will appear close together.

 

 

July 12

The now almost-full Moon will appear quite close to the star Antares tonight. Antares means “the rival of Mars’, and it’s not hard to see why, as it’s ruddy colour makes it look just like the fourth planet from the Sun. Antares is a red supergiant star, 800 times bigger than the Sun!

Today, the eighth planet from the Sun, Neptune, has completed one full orbit of the Sun since its discovery in 1846. Neptune takes almost 165 years to complete one circuit of the Sun. Neptune is too faint to be seen with the naked eye, but it is within the range of medium-and-larger backyard telescopes, if you know exactly where to look. This chart, provided by the Royal Astronomical Society of New Zealand, will help you to find it.

July 15

Full Moon occurs today at 4:40pm Sydney time (06:40 Universal Time).

July 20

Mercury reaches its greatest angle from the Sun today, so if you have a clear evening sky, why not take the opportunity to go out and spot it in the west after sunset?

Position of Mercury on July 20, 2011

July 20, 2011, 5:20pm: Mercury will be at its greatest angle from the Sun today, and visible in the west after sunset.

July 22

Today the Moon will reach the farthest point in its orbit around the Earth, called apogee, at a distance of 404,356 kilometres at 8:48am Sydney time (22:48 on July 21, Universal Time).

July 23

It is Last Quarter Moon today at 3:02pm Sydney time (05:02 Universal Time).

July 24

Slightly less than half full, the Moon will appear close to the planet Jupiter in this morning’s sky. Jupiter will be about 12 Moon widths above the Moon. Look a little further east and you’ll see Mars too. In between will be the beautiful star cluster called the Pleiades, also known as the Seven Sisters. Use binoculars or a small telescope and you’ll be delighted with the view.

Position of the Moon, Jupiter and Mars on July 24, 2011

July 24, 2011, 6:20am: The Moon and two planets—Jupiter and Mars—will be visible in the north-eastern sky before sunrise. See if you can spot the Pleiades star cluster as well.

July 25-28

In the western sky after sunset, the planet Mercury will appear close to the star Regulus (see July 5 for more information on this star).

July 28

The crescent Moon will appear very close to the planet Mars in this morning’s sky. They’ll be separated by only three Moon widths.

July 31

New Moon occurs today at 4:40am Sydney time (18:40 on July 30, Universal Time).

If you have any questions or comments on the night sky, we’d be happy to answer them. Please use the Feedback Form below. Happy stargazing!

Images courtesy IAU.

Get SpaceInfo.com.au daily updates by RSS or email! Click the RSS Feed link at the top right-hand corner of this page, and then save the RSS Feed page to your bookmarks. Or, enter your email address (privacy assured) and we’ll send you daily updates. Or follow us on Twitter, @spaceinfo_oz

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Amateur astronomy milestone

Illustration of stargazers

Thousands of amateur astronomers monitor interesting stars throughout the year. Professional astronomers make good use of the data collected.

  • Amateur astronomers monitor brightness changes of “variable stars”
  • Brightness changes reflect physical changes happening within the stars
  • Professional astronomers rely on amateur observations

A CITIZEN SCIENCE PROJECT running for over 100 years reached a key milestone this month when an amateur astronomer contributed the 20 millionth observation of a variable star on February 19, 2011.

A variable star changes in brightness over time. Records of these changes can be used to uncover the astrophysical processes within evolving star systems.

With a database going back over a century, variable star astronomers have access to a data source unparalleled in astronomy.

“The long-term study of stellar brightness variation is critical to understanding how stars work and the impact they have on their surroundings,” said Dr Kevin Marvel, Executive Officer of the American Astronomical Society. “The noble efforts of the engaged AAVSO volunteers play an important role in astronomy and help expand human knowledge.”

Amateur astronomers have been recording changes in the brightness of stars for centuries. The world’s largest database is run by the American Association of Variable Star Observers (AAVSO) and was started in 1911, making it one of the oldest continuously operating citizen science projects in the world.

Hubble image of stars

Variable stars are ones that change their brightness periodically or spasmodically. Astronomers want to know why.

“Because some variable stars are unpredictable and/or change their brightness over long time scales, it is not practical for professional astronomers to watch them every night. Thus, amateurs were recruited to keep tabs on these stars on behalf of professionals,” Dr Arne Henden, Director of the AAVSO, said.

20 million and counting

The 20 millionth observation was made by Dr Franz-Josef “Josch” Hambsch of Belgium. The observation was of GV Andromeda, which is in a class of older, pulsating stars smaller than our Sun.

I like these stars because you can see their entire variation cycle in one night. There have not been many recent observations made of this particular star, so that is why I am monitoring it,” Hambsch said. Hambsch is also a member of the Belgium variable star organisation, Werkgroep voor veranderlijke sterren (WVS).

The AAVSO currently receives variable star brightness estimates from about 1,000 amateur astronomers per year. Special equipment is not necessarily needed. While some variable stars require high-tech equipment, others are bright enough to be seen with the unaided eye.

Also, the AAVSO has a network of six robotic telescopes that are available to members free of charge.

Invaluable contribution by amateurs

Making an estimate of a variable star’s brightness can be a time-intensive procedure and requires careful training. The observer must identify the star in the sky and then compare its brightness with those of other, nearby stars that are steadfast in their own brightness.

The process can range from less than a minute to many hours per estimate, but typically takes about five minutes. At that rate, observers have invested the equivalent of about 1.7 million hours of time in collecting observations for the database.

Assuming a current median salary of US$33,000, this would be the rough equivalent of US$27.5 million worth of donated time if all the observations were reported today.

“The reality is these observations are invaluable. The database spans many generations and includes data that cannot be reproduced elsewhere. If an astronomer wants to know the history of a particular star, they come to the AAVSO,” Henden said.

More information:

AAVSO

Variable Star Section, Royal Astronomical Society of New Zealand

Adapted from information issued by AAVSO. Illustration courtesy Nico Camargo and AAVSO. Star image courtesy NASA / ESA / Jesús Maíz Apellániz (Instituto de Astrofísica de Andalucía, Spain).

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Planetary line-up this week

Diagram of a planetary line-up May 19-22.

Diagram of the planetary line-up May 19-22, as seen from the perspective of an observer in the United States.

  • Moon, two planets & star line up
  • Happens from May 19-22
  • Easy to see – don’t need a telescope

The bright star Regulus joins the Moon and the planet Mars to form a beautiful lineup high in the southern sky (for US observers; in the northern sky for S. Hemisphere observers) at nightfall May 19-22, according to the editors of the University of Texas’ StarDate magazine.

And the best part of this stargazing spectacle is that you won’t need a telescope or binoculars to enjoy it. All you need is your eyes and a clear sky!

Starting on May 19, Mars will be in good view above the Moon as night falls. Regulus shines to the left of Mars, slightly higher. Regulus is the brightest star of Leo, the lion, and is more massive, hotter, and brighter than the Sun. Mars looks like a bright orange star.

On May 20, Regulus will be a little to the upper right of the first-quarter Moon, with bright orange Mars farther to the Moon’s right. The trio will form a wide, skinny triangle. They will be high in the sky at nightfall, and drop from view by around 2:00am

On May 21, the Moon will lie between Saturn (due south) and Mars (in the southwest) at nightfall. Saturn looks like a bright golden star.

By May 22, the Moon shines below Saturn, high in the south at sunset.

Adapted from information issued by StarDate magazine.

Moon, two planets & star line up

Happens from May 19-22

Easy to see – don’t need a telescope

The bright star Regulus joins the Moon and the planet Mars to form a beautiful lineup high in the southern sky (for US observers; in the northern sky for S. Hemisphere observers) at nightfall May 19-22, according to the editors of the University of Texas’ StarDate magazine.

And the best part of this stargazing spectacle is that you won’t need a telescope or binoculars to enjoy it. All you need is your eyes and a clear sky!

Starting on May 19, Mars will be in good view above the Moon as night falls. Regulus shines to the left of Mars, slightly higher. Regulus is the brightest star of Leo, the lion, and is more massive, hotter, and brighter than the Sun. Mars looks like a bright orange star.

On May 20, Regulus will be a little to the upper right of the first-quarter Moon, with bright orange Mars farther to the Moon’s right. The trio will form a wide, skinny triangle. They will be high in the sky at nightfall, and drop from view by around 2:00am

On May 21, the Moon will lie between Saturn (due south) and Mars (in the southwest) at nightfall. Saturn looks like a bright golden star.

By May 22, the Moon shines below Saturn, high in the south at sunset.

Adapted from information issued by StarDate magazine.