04 March 2021

Brightest asteroid Vesta in Opposition

 

The brightest asteroid Vesta is in opposition today, March 4th 2021. It is easily visible through small binoculars even in the light polluted city conditions. Vesta will rise in the east as sun sets in the west. sun, earth and Vesta will be in the same line with earth at the center, this is called opposition. 


Vesta Opposition


Vesta is now placed in the constellation of Leo very close to the bright 3rd magnitude star Theta Leonis. You can spot the asteroid Vesta just 1 degree 15 minutes north east of Theta Leonis. Around 8pm the asteroid will be well placed for spotting but if you have buildings or trees blocking the horizon then you may have to wait until 10pm to spot the asteroid.


Vesta in Leo

Looking through the binoculars or telescope the asteroid will appear as a star, with no hint of shape. This is because of the distance between the earth and Vesta which is now at 1.36 AU(203,453,379km) and the size to the asteroid is 262km in radius.


Vesta Position in Leo

Vesta will be closest to the earth on March 9 2021.


Following Vesta:


With a pair of binoculars or telescope you can notice the movement of Vesta. Choose a couple of stars in the field of view and make a sketch of the field or you can take a photo of the field. With regular observations over the days can show the movement of Vesta with non-moving stars in the field.


Vesta is moving fast at 1 minute of arc in March. If you continue to track Vesta every night or every couple of days you will notice that the distance moved by Vesta is slowing down and in middle of April 2021 Vesta will appear stationary for couple of days and slowly increase the speed as days follow.


Vesta tacking 



You will also notice that from March to April the asteroid Vesta will be moving towards western direction in the Sky, but from first week of May the asteroid will appear moving towards eastern direction in the sky. This is due to the fact that Vesta will be in retrograde motion until April and appear to move towards west and later it will start moving in east. 

Along with angular velocity and direction you will also notice that the asteroid Vesta magnitude also starts dropping. Now in March 2021 Vesta magnitude is 5.9 and post retrograde, that is after April the magnitude of Vesta will drop to 7.2 and it will keep dropping. You can notice this drop in brightness comparing with the stars you have chosen for reference.


Finding and tracking Vesta not only improves the skill of finding objects in the sky using star hopping, it will also make the hobby interesting helping in understanding the concepts like field of view, angular motion, retrograde motion and Magnitude system.


Good Luck Observing!

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