Minor Planet, Asteroid 4 Vesta at Opposition

   Wednesday 9 May the minor planet, Asteroid 4 Vesta will be at its perihelion for this orbit. Perihelion is when a solar orbiting object is at its minimum distance, or closest to the Sun. Asteroid 4 Vesta is one of the largest main belt asteroids with a diameter of about 525 km (326 miles).

   At this perihelion 4 Vesta will be 2.1517 AU (321,889,738 km; 200,013,010 miles) from the Sun. At this distance 4 Vesta will reach an apparent magnitude of around 6.0 meaning that it could be visible using binoculars. 4 Vesta lies within the region of the Milky Way and about 1o from 4 Vesta is the Omega Nebula, M-17 (apparent magnitude 7.0), and around 4o from 4 Vesta is the Eagle Nebula, M-16 (apparent magnitude 6.5).

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

Between a Rock and a Hard Place

   Friday evening, April 8th at sunset or shortly thereafter look toward the western horizon for a very thin 1.5-day young waxing crescent Moon. There you will find the Moon between two rocky objects, an asteroid and a planet.
   Down to the right from the Moon is the innermost planet Mercury shining at nearly 1st magnitude. Just up to the left and less than 1o from the Moon is the asteroid 4 Vesta, which by contrast currently has an apparent magnitude of nearly 8.0 making it an object visible in binoculars and telescopes.
   At 4 UT April 9th the Moon will occult, pass in front of Vesta, but this occultation will only be visible from the Philippine Islands, and Hawaii and a few other islands in that part of the Pacific Ocean.

   Read more about Vesta at Wikipedia, or at the NASA Dawn mission web site.

   
   
   
   

Caution: Objects viewed with an optical aid are further than they appear.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

The Besta of Vesta

vesta-7oct   Yeah I know, the title is bad but it was the besta I could do at the moment.
   Asteroid Vesta, is the second largest asteroid in the main belt of asteroids between Mars and Jupiter. It is also the second most massive asteroid after the former asteroid, now dwarf planet, Ceres. Vesta is also the brightest and easiest of the main belt asteroids to see from Earth, and this month could be a good time to dust off the binoculars or telescope and take a look.

   Asteroid Vesta rises at around 8 pm local time and is currently located within the western side of the constellation Cetus the Whale, and over the next several days will be passing by a 2nd magnitude star, Iota Ceti. That is the ‘dot’in the center of the binocular field.

click on graphic to see it larger   To be fair, taking a look at an asteroid, even one like Vesta, is about like looking at a star. In one night the only apparent movement of the object is from Earth rotation. However careful observing, perhaps making a sketch or taking a picture of the area of the sky where Vesta is located every couple of days the motion of the asteroid should become apparent as it will be the only ‘star’ moving relative to the other stars in your sketch or picture.
This animated graphic using inverted colors is simulating a view with 10×50 binoculars. It shows the movement of Vesta daily between the 8th and 31st of this month. Click here to see the same graphic with the regular colors.

   Get very specific observing information for your viewing location from the Heavens Above web site. Choosing your viewing location is as easy as zooming in on the Google map and setting the marker where you view from. Click on update to set your location. Once you have set your viewing location you can then choose from many options. Obviously choose asteroids, then choose Vesta!

   Learn more about Asteroid Vesta and Dwarf Planet Ceres at NASA’s Dawn Mission web site.

   Traverse the Vesta terrain at NASA’s Vesta Trek web site.

   
   
   
   

Caution: Objects viewed with an optical aid are further than they appear.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Moon – Jupiter – Asteroid- Star Cluster Conjunction

   Saturday evening May 23rd the waxing crescent Moon will be close to Jupiter, two open star clusters (M-44, M-67), and an asteroid. As this graphic shows, within the field of view of 7×50 binoculars, you can see the Moon, Jupiter, and the asteroid 3 Juno. A slight shift in the viewing brings either of the two open star clusters into the binocular field of view.

   M-44, also known as the Beehive Cluster, is a group of around 1000 stars at a distance of 500-600 light years and shining with a combined magnitude of approximately 4.0. To the naked eye M-44 looks more like a nebula but resolves nicely into its component stars with optical assistance. M-67 in comparison is much dimmer at a distance of 2500-3000 light years, and with only around 100 stars this open star cluster shines with a combined 6th magnitude brightness.

   Asteroid 3 Juno was the 3rd asteroid to be discovered and is one of the largest asteroids in the main belt between Mars and Jupiter. Juno has an apparent magnitude of around 7-8 so it is within the viewing capabilities of binoculars albeit as a star-like point of light.

   
   
   
   

Caution: Objects viewed with an optical aid are further than they appear.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Double or Triple Dating?

Click on graphic to see it full size.

Click on graphic to see it full size.

   Tuesday evening after local time for sunset there will be an opportunity to see several interesting pairs of celestial objects divided among three planets, our Moon, and several asteroids as this graphic shows. Jupiter is the single this evening, over the southwestern horizon near the twin stars of Pollux and Castor. Higher above the southern horizon is the constellation Leo the Lion with its distinctive backward question mark star pattern. At the bottom of the question mark is one of the celestial pairs, the star Regulus and the nearby asteroid 2 Pallas. Continuing eastward is the Dwarf Planet Ceres paired up with one of the larger asteroids, Vesta. Mars and the blue-white star Spica form the base of a triangle with the two asteroids as the point. Looking further eastward for the third celestial pair, and outshining everything else is the very near full Moon and a few degrees away the planet Saturn.

Click on graphic to see it full size.

Click on graphic to see it full size.

   As this graphic shows the asteroid 2 Pallas is close enough to the star Regulus in Leo so that both fit within the field of view of binoculars. Regulus shines at magnitude 1.4 while about 2 degrees away is the 8th magnitude asteroid Pallas.

   
   
   
   
   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Venus Gets the Hebe (Jeebees)!

Click on graphic to see it full size.

Click on graphic to see it full size.

   Yeah, I know that title is a bit of a stretch but what the heck! How often will a bright planet like Venus come close to an asteroid? Especially one named Hebe (pronounced ‘heebee’). So, tomorrow morning, Sunday the 27th, Venus will be within two degrees from asteroid 6 Hebe as this graphic shows. The contrast in apparent brightness between these two is considerable however. Venus has an apparent brightness (magnitude) of -4.1 compared with Hebe’s +9.4.
   Asteroid 6 Hebe is the 5th brightest asteroid and was the 6th asteroid to be discovered (1847). It is an elongated or potato shaped asteroid with an average diameter of approximately 115 miles (185 km). From mythology Hebe is the Goddess of Youth, young folks, rather than a goddess with powers to make someone younger.

   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Asteroids at Opposition

vesta-ceres-ani   Vesta, aka 4 Vesta, the third largest of the asteroids within the main asteroid belt between Mars and Jupiter reaches opposition Sunday 13 April. Two days later, 15 April, the closest Dwarf Planet to Earth, the former asteroid Ceres also reaches its opposition. Opposition is an arrangement with any outer planet or asteroid that is further from the Sun than the Earth. At opposition the Earth is between, in this case, either Vesta or Ceres, and the Sun. At opposition, like the full Moon, a planet or asteroid rises at sunset and is above the horizon all night and then sets at sunrise.

   Ceres, with an average diameter of 590 miles (950 km), as an asteroid was the largest and now as a dwarf planet is among the smallest if not the smallest object with enough mass to become round and thus qualify for a lateral promotion to dwarf planet status. Vesta has an average diameter of 525 km (326 miles ) and was the fourth asteroid discovered, in 1807. Vesta was also just recently visited and explored from orbit by NASA’s Dawn spacecraft. That spacecraft left orbit around Vesta in September 2012 and it is now heading for arrival at Ceres during the spring (northern hemisphere) of 2015. Vesta is also the brightest asteroid as seen from Earth and so the next few weeks offer an opportunity to perhaps see this asteroid and Ceres as they both move into and then past opposition and then moving in retrograde, westward.

Vesta and Ceres 10 April to 30 April.

Vesta and Ceres 10 April to 30 April.

   This animated graphic shows the westward motion of Vesta and Ceres as the two pass by several stars, some of which have a magnitude around Vetsa’s 5.39 and Ceres’s 6.5.

   Neither Ceres nor Vesta move fast enough to see any change in their position relative to any nearby ‘reference’ stars for at least a day or so. See if you can catch a ‘star’ changing its position relative to other stars by drawing a star chart of the stars you see in the field of view of your binoculars or telescope eyepiece. Repeat the drawing the next night, or wait another night. Do this a few times and by comparing your drawings you may find one of the dots you made for stars has shifted its position. That is the asteroid. Congratulations!

The Moon at 2 am CDT

The Moon at 2 am CDT

   Throughout this period the Moon will change from its waxing gibbous phase, pass through the Earth’s shadow for a total lunar eclipse, then begin its waning gibbous phases all the while passing past the asteroids Vesta, Ceres, Mars, Saturn, and a bunch of other celestial delights.

   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.