24 February 2014

Daytime Venus Occultation

Daytime skies are little boring to people with only one star to observe. Occasionally we get treats like solar eclipse and transits, amazing celestial daytime events that make the long wait worthwhile.  On 15th February 2013, a meteor entered earth atmosphere and as it burnt up, it lit up the skies of Chelyabinsk, Russia. Apart from these rare events, the actions in the skies hide behind the glare of the sun during the day.
Lunar occultation of stars and planets are events normally associated with night sky. Moon occults stars and planets during daytime too but we cannot see these events because, the bright Sun outshines everything in the sky. However, every rule has an exception; we see Moon during daytime without any difficulty, and with practice, we can also spot Venus with naked eye and it is an easy target for telescope in the daytime.
This February 26th there is an event involving Moon and Venus during daytime(Readers of AKASHA will already know this from JAN-FEB issue). Moon will occult Venus on this day. Occultation of planets by Moon is rare event, for example from Bangalore the next Occultation of Venus by Moon will be in 2023 March 24th.
We have to take Extreme precaution when planning to observe the event, equipment  always has be pointed away from the Sun. Even very small duration exposure to Sun’s rays through telescope or binocular can damage the eyes permanently.
The brightness of both Moon and Venus makes it good challenge for daytime occultation observation with Moon at crescent phase and Venus close to half phase at -4.5 magnitude, will be a great sight through the eyepiece.
Venus will disappear from the lit part of the crescent Moon and reappear from the dark part of Moon. Venus will be close to 15 minutes of arc from the brighter edge of the moon at 10:30am IST, both should fit in to the same field of view in a 6-inch telescope.
Here are the times and altitude of Moon for February 26th Occultation:
Venus will disappear at 11:05am IST and at this time the altitude of Moon will be 53 degrees.  Venus will reappear from the darker side of the Moon at 12:29pm IST. The altitude of Moon at the reappearance of Venus will be 38 degrees.
Hope for clear skies.