The Great Indian Eclipse?

News channels have started filling in the news about the brand new Solar Eclipse in town.

This eclipse occuring on July 22nd could have been the  “Great Indian Eclipse” – due to the long time of totality (longest in 21st century, with 6+ minutes of totality – although this may not happen in India), had it not occured in the month of July, and  at the specific time of the day  it occurs.

Solar Eclipse of 1999; Image from Wikipedia

(Image taken from here: http://en.wikipedia.org/wiki/File:Solar_eclips_1999_4_NR.jpg )

It is monsoon season in India now, and the weather gods may not co-operate with skywatchers. And the eclipse occurs at sunrise, so the Sun is pretty low in the horizon when totality starts.

But whoever can catch it, be it in India, or China, would have their chance of their life time.

“This eclipse is a bad omen” – ” 3 eclipses in one month happened during Mahabharat war”, “The last time this eclipse occured was 360 years ago”, Not good for …. blah blah blah”…. – there is quite a lot of negative publicity in Indian media already.

How much of  this could be  truel? Hard to seperate wheat from the chaff.

I am surprised at how easy it is for the media to fool people. Again and Again they have done it. So predictably. Last year they reported  how rare it was to see two eclipses in a row. This year they might talk about how rare it is to see 3 eclipses in a row!

Here are some eclipse fun facts  (not in any specific order)

• Eclipses repeat  in about every half-year (called eclipse seasons)
• Each eclpse season lasts for about 40 days. If the Sun and the Moon are in the right places around the nodes (rahu & ketu) , and more importantly, if you are at the right location you might see an eclipse
• There can be a maximum of 7 eclipses occuring in a calendar year, but that’s kind of rare
• In each eclipse season – one, two or three eclipses can occur – 2 solar and one lunar, or 2 lunar and one solar
• All eclipses in an eclipse season may not be visible from the same place on the earth, but it is not all that rare to see two eclipses in the same season at a place. For example, this seasons 3 eclipses can be seen from some parts of Indonesia. . (Two of the lunar eclipses in this season are penumbral, and so there is nothing to see, really – That’s another matter )

So if you get an e-mail telling how rare this eclipse triad occuring on July 7th, July 22nd and August 6th is – please hit delete, and do not forward it to anyone!

-neelanjana

A Long Drive to Mt Hamilton

Exactly 25  miles long, that is. That is how far the summit of Mt Hamilton is from Downtown San Jose. But what makes this 25 miles really long is the change in elevation – from 85ft above sea level to 4209 ft above sea level.

I made this ‘long‘ trip couple of weeks ago. Sort of  funny, because Mt Hamilton and the domes on top are part of the horizon in my view every day for the last 10 years! So near, but so far! Here are some pictures from that drive.

The 4000+ ft change in elevation means there is no shortage of twists and turns and curves. The moment you go past one blind curve, you will face the next! Be ready for motion sickness!

Curves and Turns!

James Lick Observatory is located atop Mt Hamilton. This was the first mountaintop observatory ever built, around the end of 19th century.

An old picture of the observatory

When it was built, it had the world largest Refracting telescope (36″ inches) . This telescope  is still functioning, and being made good use of.

The 36 inch refractor

Now there are few more telescopes atop Mt Hamilton; A 120 inch reflector, a 36 inch reflector and a 100 inch Automatic Planet Finder -to name a few. These are a short walk away from the original observatory, but public access to these domes is limited.

Newer Domes

Mt Hamilton being one of the highest peaks around the south bay, there is an uninterrupted view in all directions.

The picture on the top of my blog page  with  a view of the Moon rising behind the observatory in Mt Hamilton is taken from – “Astronomy Picture of  the Day” ; courtesy NASA.

More information about Lick Observatory can be found here.

-neelanjana

Another Yugadi

Many people in South India celebrate Yugadi on 14th of April every year. This includes districts from coastal Karnataka as well.

You may wonder  how this festival falls on the same day everyday? This is because it is a festival based purely on the solar calendar – instead of the luni-solar calendar which is used to calculate the date the dates for most other Indian festivals.

This is the day when the Sun enters mESha rAshi (Aries). But if you are used to read your predictions from the newspapers everyday, I’m sure you’d have noted they assign Aries to those who are born between March 21st to April 21st.

So where is the catch? Who is right?

Both , in their own ways.

The year used to be calculated from the Vernal Equinox. Back in that time when constellation boundaries were drawn, the Vernal Equinox also coincided with the time when Sun entered the boundary of Aries and hence the Zodiac begins with the constellation Aries. This point (where the ecliptic, and the celestial equator crossed each other was termed the “First point of Aries”, since it actually was close to the beginning of this constellation boundary. This was made the starting point (zero degrees) for all celestial calculations.

Due to precession, Vernal Equinox falls behind (in time) every year and now it occurs around the 20th/21st of March. The western astronomy found a way to get out of this problem by moving this reference point, and so the “First point of Aries” does not occur near the real boundary of the constellation Aries. However, it is still called by the same name, and causes some confusion. By doing this, the Vernal Equinox, always falls at the time when the Sun is at the “First point of Aries”.

Indian astronomy, on the other hand,  does not move the reference point for the calculation of festivals. Hence, the mESha sankramaNa is celebrated on the day Sun enters the real boundary of Aries,  and not when the Sun is at the “First point of Aries”. The equinox and the beginning of the year have been thus de-linked.

Here are couple of sky simulations showing the position of the Sun, around these days.

Around March 20th,2009 – Beginning of the ‘tropical’ year

Around March 20th,2009 - Near Vernal Equinox

Around April 13th, 2009 – Near the beginning of the traditional Indian solar year:

Solar position near the beginning of Indian solar new year

-neelanjana

Last Conjunction Of 2008

As the year is coming to a close, we can witness the last planetary conjunction for the year.

Jupiter and Mercury are coming closer in the evening sky. Normally Mercury is a very elusive planet to find, not because it is faint but because it is always very close to the horizon whenever it is visible – early morning or early evening. In the absence of a marker star or planet to locate Mercury, it could be a hard find. And that’s what makes this conjunction interesting.

Jupiter and Mercury are very close in the evening sky now, and if you watch just after the sunset from a location with a clear view of the western sky, you should be able to spot the planets without much difficulty.  Venus is a little higher in the evening sky too shining brightly. Mercury now has an apparent magnitude of -0.7. To give a comparison, except for Sirius, the brightest star visible to the naked eye, no other star in the night sky appears  much brighter than this.  The  proximity to Jupiter makes it easy to spot the planet. That’s all. And of course,  the twilight  might make it appear little fainter than what a -0.7 magnitude object should look like.

Here are a few screen-shots taken using Stellarium.  This is taken for an observer in south Karnataka, India (about 13degrees North). However, if you are somewhere else, the same timings should work for you too; but remeber that the Moon is the fastest moving body in the Sky. So the relative position of the Moon (with respect to the planet pair) might be different than what these pictures show.

Here is the evening sky of 12/30/2008.  (about 15 minutes after sunset)

Evening Sky - 12/30/2008 ; Just after sunset.

Here is the evening sky on 12/31/08; About 15 minutes after sunset.

12-31-08; Evening sky

Evening sky on new year's day - 2009

Notice the relative movement of Mercury and Jupiter. Also notice the crescent moon moving out of the view (in the screenshot)  as it goes higher in the sky. In the sky, of course, it would appear larger and higher.

I managed to get a glimpse of the planets last night, since the clouds moved away from the western horizon just in time.  Tonight, it is to be seen how the weather god Varuna, c0-operates .

If you have clear evenings the next few days , do not forget to head out right after sunset and check out!

-neelanjana