Vesta at its brightest for 58 years

Saturn and Vesta
Saturn and Vesta on 20 June 2018. Photo: Robin Scagell

The minor planet (asteroid) Vesta is currently bright enough just to be seen with the naked eye – and won’t be quite as bright again for 11 years. On the downside, it’s quite low in the sky as seen from the UK, in the constellation of Sagittarius. But fortunately, the bright planet Saturn is nearby, making it easier to spot. It is an easy object using any binoculars.

Vesta is not the largest of the asteroids, with an average diameter of just 525 km, but its unusually bright surface means that it’s the brightest. Despite being just visible to the naked eye from time to time, it was not spotted until 1807.

Occasionally its orbit brings it slightly closer to Earth than usual, and this is one of those times. It won’t be until July 2029 that it again gets as bright as this. So don’t hang around! But this year’s event isn’t Vesta’s brightest ever: it reached magnitude 5.2 on 5 July 1960, for example.

To find Vesta, first locate Saturn by looking to the southern part of the sky in the late evening. It is the brightest object in that part of the sky, fairly low down – literally skimming the rooftops in many cases. It is due south about 1:30 am BST. Now use the map below to locate Vesta for the date you are observing compared with the position of Saturn. It won’t stand out with the naked eye, so use binoculars. In this case, small or low-magnification binoculars are better than large high-power ones, as they will show you more of the sky at a time.

Vesta 2018
Positions of Vesta during June and early July 2018 compared with the position of Saturn. The circle shows a 5º field of view, typical of binoculars.
Vesta 2018 positions
Detailed positions for Vesta, showing stars to magnitude 9.5.

Vesta is moving quite rapidly, so remember that the tick marks on its path are for midnight on the date in question – if you’re observing on the 24th, say, before midnight, it will be close to the next date’s position. If you are using sky mapping software to locate it, make sure you are using the very latest update, as predictions made with software updated even a few months ago are slightly in error.

Taking photographs just a night apart will show its change in position clearly. You don’t need a camera driven to follow the stars – with good modern cameras, just a few seconds’ exposure on a tripod-mounted camera at a high ISO setting and standard lens focal length will be sufficient to show it, though longer exposures on driven cameras will reveal the Milky Way and some deep-sky objects nearby.

 

Vesta closeup
Vesta photographed with 200 mm lens on 20 June 2018. 30 sec exposure, f/6.3, ISO 1600. A driven mount was used. The open cluster M23 is at top left. Photo: Robin Scagell
Saturn and Vesta
Saturn and Vesta photographed from Walmer, Kent, on 22 June. It has moved westward compared with its position on 20 June. Photo: Paul Sutherland

Spot Jupiter tonight

Jupiter in sky
Jupiter shines between the rooftops. Photo: Paul Sutherland

There are two bright planets in the evening sky at the moment – Venus, visible in the west after sunset, and Jupiter, which you can see in the south-east in the evening sky. During the night, Jupiter moves to the south, and this is just about the best time this year to view the largest planet in the Solar System.

It reached its closest point to Earth for the year on 9 May, but it’ll be easy to view for another couple of months. It is fairly low down in the sky this year as seen from the northern hemisphere, so if you have rooftops or trees to the south-east, choose another location to spot it.

Jupiter
Jupiter, photographed on 7 May 2018 using a 130 mm Sky-Watcher reflecting telescope. The Great Red Spot is to upper left and the satellite at lower left is Ganymede, Jupiter’s largest moon. South is upwards, as seen through an astronomical telescope. Photo: Robin Scagell

Take a look through binoculars and you may see its four major moons on either side. They move from night to night, so not all four might be visible when you look as one or two could be too close to the planet to be visible.

Even a small telescope will show the darker equatorial belts on the planet, and maybe even a bit of detail on them. You’ll probably need to study the planet carefully if you’re not an experienced telescope user, but don’t give up on them. With larger telescopes — say with lenses or mirrors 100 mm or more in diameter – you might even spy the Great Red Spot, a vast continuing storm in the planet’s cloud belts.

Later in the summer Mars and Saturn will be around – so come back here for more info.

Nova in Perseus

Position of nova (circled) as seen from the UK looking north-west at 11 pm BST

A new transient object has appeared in the constellation of Perseus, with the most recent observations putting it at magnitude 6.2. This is the brightest nova-like object to appear in the northern hemisphere of the sky since 2013. The object is not far from Capella, in Auriga, which is best seen in the late evening sky.

The nova is in the same position as the variable star V392 Persei, a U Geminorum-type variable with a normal range between magnitudes 14.1 and 16.9. These close binary stars are also known as dwarf novae, and vary in brightness as material from one star falls onto the other.

This particular star is normally around magnitude 15, though it experienced an outburst to mag 13 in 1999. However, an outburst of the size shown by this star is unprecedented.

The star’s position is RA 04h 43m, Dec +47º 21′. The map below shows a more detailed view of the area, with stars shown to magnitude 8.

 

Nova Persei 2018

Latest reports

The nova appears to be declining fairly rapidly in brightness. Estimates published by the Central Bureau for Astronomical Telegrams on CBET 4515 give values around mag 7 around 9 pm BST on 30 April, and estimates by SPA members Tracie Heywood and Bob Steele at around 11 pm BST give 7.3 and 7.2. Tracie has provided a link to an AAVSO chart for V392 Per that gives comparison stars in the area.

8 May 

Visual reports from the AAVSO show the nova to have faded to about magnitude 8.9.

The photo below, taken at 23.30 BST on 7 May, shows the object (arrowed) with nearby stars in the area and a chart for identification of the object. The star immediately to the left of the nova is magnitude 9.3.

Position and brightness of Nova Persei 1918 on 7 May 2018. The lower map shows the position of the object compared with Capella (SkyMap), with the area of the photo marked with a rectangle

 

Gallery

Nova Persei
Nova Persei, arrowed, together with Capella (bright star at left) and the Haedi stars. Photo by Stuart Atkinson, Kendal, Cumbria, on 30 April 2018
Nova Persei 2018
A photo taken at 0h UT on 1 May shows the nova at about magnitude 7.3. Capella is the bright star at left. The inset shows a stack of 10 images taken through high cloud using an undriven camera. Photo: Robin Scagell

Lovely Lyrids

Lyrid meteor
Lyrid meteor (upper right) photographed by Paul Sutherland from Walmer. Kent on 22 April. The other trail, partly in cloud, is an aircraft.

SPA member Paul Sutherland took some excellent photos of April’s Lyrid meteor shower from his home in Walmer, Kent. His balcony overlooks the English Channel, and offers good skies despite an LED streetlight in full view! Here are some of his results, taken with a Fuji X-M1 camera equipped with a Samyang 12 mm lens. Exposure times were 20 seconds each shot at ISO 2000.

Lyrid meteor
Closeup of the meteor in the photo above, taken at 02:40 UT on 22 April.
Lyrid meteor
Photo taken at 02:12 on 23 April, with meteor in Lacerta
Lyrid meteor
Meteor photographed at 02:20 UT on 23 April, in Pegasus
Lyrid meteor
A Lyrid zooms through the Milky Way in Cygnus, at 02:33 on 23 April

A good year for Lyrids?

Lyrid simulation
A simulation of the 2018 Lyrid meteors, as seen about 3 am BST on 22 April, using the Stellarium program

The spring is not usually the best time for meteors – shooting stars – but a welcome exception is the Lyrid meteor shower. These appear around the third week of April, with their peak on 22 April, and this will be a good year to view them, given clear skies, and as long as you’re prepared to wait until the early hours of the morning! Read more

Spot the Space Station

Spot the Space Station

The International Space Station (ISS) is in our evening skies again between 26 January and 13 February. You’ll be able to see it every clear night until 11 February from anywhere in the UK, gliding through our skies as a brilliant star. It appears brighter than most planes, despite being hundreds of kilometres away, and on good passes you can watch as it passes well over central Europe. Amaze your friends with your predictive powers! Read more