Feeds:
Posts
Comments

Archive for the ‘Astronomy’ Category

To add to his numerous other discoveries, here is a new Supernova to Vishnu’s credit!! This is a very bright one! .. 14.3 mag. This is roughly the brightness of Pluto(I mean the apparent brightness, as seen from earth) Such bright ones are pretty rare. Here is the page from Smithsonian which lists recent supernova discoveries.

“2006E” is the one that Vishnu shares with Puckett (a well known supernova hunter) and others.You can easily make out that there arent many in the mag 14** range. Here is an image of the supernova from Vishnu’s website.Many congratulations to Vishnu!

**In the magnitude scale a lesser ‘magnitude’ implies greater brightness.
Such a definition is for purely historical reasons. This is a logarithmic scale.

Read Full Post »

24 asteroids and counting…

Amateur Astronomers are a rare breed in India. This might be due to a variety of reasons. The primary reason is probably the reasonable financial commitment involved in this hobby. Ofcourse, small pockets of enthusiastic amateurs exist. But when compared with countries like the US, the numbers here are much lesser. There aren’t many telescope makers either.

Given this, the first Indian amateur astronomer to discover an Asteroid must be quite a special guy! Vishnu Vardhan Reddy is the one who accomplished this feat and he now has 24 asteroid discoveries to him name! I first met Vishnu on a mailing list. Since then, I had been paining him to give a lecture at our Astro Club. Finally, he was in India for a month and gave a lecture at our Astro Club on Jan 3rd.

Vishnu’s path to these discoveries is pretty fascinating. After getting his masters in Communcations, he worked as a Science journalist for the Asian Age (based in Delhi). He was into amateur astronomy since his school days, thanks to Prof.Devdas in Chennai. Infact, most amateurs in Chennai owe their initiation to this dedicated man who is now 80+ and is still making telescopes! Do read Vishnu’s recollections about his childhood. After learning from Prof.Tom Gehrals that even amateur astronomers could make significant contributions to asteroid hunting, Vishnu took serious interest in finding asteroids. An asteroid is detected by observing its motion wrt background stars. One needs to take periodic photographs of the sky to make out an asteroid. Ofcourse, the larger a telescope you have at your disposal, the better equipped you are. Quality photography equipment is also necessary. Vishnu got a 12″ Meade scope thanks to an unexpected loan from a friend whom he had never met!!

Gregg quickly asked me if I could come up with the money later. I said I don’t have anyone but I can try for sure. He took out his Credit Card and ordered the telescope right away. I was shocked at first. Here was a guy who spent $3,000 on a telescope without even seeing my face!

Mind you, these are atrociously costly toys. Today, the cost of this Meade scope would be ~2 lakhs . But, to his dismay, Vishnu found that a 12″ Meade is not sufficient to make asteroid discoveries on a regular basis! The very purpose of collecting $3000 from various sources seemed lost. However, things fell into place during a visit to the US. He met experienced asteroid hunters and finally found his first asteroid! Do read his rather elaborate account of this discovery.

With $200 in pocket, I took a 3-day bus journey from Michigan to Arizona in the last week of June. The bus went through 7 states arriving in Tucson 10 hours late!

Phew!

Curious, I asked what they were and he replied, “Dude, you have found 2 asteroids.” Not sure if that’s true, I went and checked the MPchecker again so that they got the numbers right. Yes, they were new and I found them.At last after 3 years of chasing all kinds of things, I finally got not one but 2 asteroids. Too tired to enjoy the new discoveries, I crashed on the bed at 5.30 pm.

The whole thing must have been quite an ordeal!

After this, he switched fields and is now into Professional Astronomy. But, he still tweaks around with amateur scopes, sets up remote observatories and makes quite a lot of asteroid discoveries with them. His latest one was a binary asteroid near the Earth. He told me that this is the first such discovery using amateur equipment. Congrats and BOL to Vishnu for future discoveries!

Read Full Post »

GMRT.. recent stuff.

This isn’t a post explaining GMRT to everyone (like my SDSC post). I would love to do it.. but even a reasonable explanation will take a long time to compile. Here , I have just collected a few media reports reg GMRT:

I came across this article on TIFR and its outposts in the latest issue of Frontline.

[…]the GMRT itself is a unique research facility located in Narayangaon near Pune. It consists of 30 fully steerable gigantic parabolic dishes, each with a diameter of 45 meters. The dishes are placed over an area of 25 square kilometers, forming an incongruous landscape of vineyards interspersed with gigantic dish antennas […]

Apart from the work noted in the Frontline article, another prominent discovery was that of an energetic pulsar, a few months back. See the DH report here. In its India Special, New Scientist carried a wonderful article on GMRT.

[..]Through clever innovation, such as using a mesh of fine wires to form the reflecting surface of each dish, Ananthakrishnan and his colleagues, led by NCRA’s Govind Swarup, have created a revolutionary, low-cost design. The entire telescope cost $12 million[..]

Here is a nice pic of a dish [from NCRA]

GMRT is a fabulous facility, amongst the very best in the world when it comes to Radio Astronomy. India is now a leading center for Radio Astronomy. It is also part of the team of countries looking into the Square Kilometer Array , the next generation Radio telescope. It is quite an ambitious project. The Indian page for the project is here. A recent IE article on this specific project is here. Beware about the number quoted against ‘area required’. It says 1 million sq Km.(1/3rd India) 🙂 .. this must be wrong. The actual conference website talks about 1 million sq.m . [An aside.. This indicates the poor quality of science reporting in India. Doesn’t 1 million sq km sound odd?? I wonder why the reporter didn’t get it checked]

Hope that u enjoyed the various links… I will make a detailed post on GMRT at a later point.

Read Full Post »

[via Astro Blog ]
Close on the heels of the International Year of Physics, we could possibly have the International Year of Astronomy, to mark the 400th anniversary of the use of an astronomical telescope(ofcourse, by Galileo). This would require the approval of the UN General Assembly. The Royal Astronomical Society and the International Astronomical Union have made their proposals to this effect.
I have also added a list of very good Astro-related blogs to my blogroll. At the minimum, you can be assured of stunning pictures, on a regular basis, from these blogs. And they will also keep you posted on the latest in the world of Astronomy. BadAstronomy is a personal favorite of mine. Happy surfing!

Read Full Post »

Hoax Alert!

Have you heard of Mars coming close this August?.. and looking as big as the moon? Beware!.. the email that told you this is full of rubbish. Though this is a very old ‘forward’.. it seems to have gained in popularity in the recent times..at least with people around me. There are many out there who have taken this forward to be true at face value..this is to all of them. I am quoting a reply by Varun in another mailing list. The contents of the original ‘forward’ are prefixed by a ‘>’.

> *Subject:* First Time in Human History
>
> *Mars is going to be a second moon of earth for a day. *
>
> *Hi all,.
> *
>
> *NO ONE ALIVE TODAY WILL EVER SEE THIS AGAIN. *
>
> *The** Red Planet (MARS)** is about to be spectacular! This month and
> next,
> Earth is catching up with Mars in an encounter that will culminate in the
> closest approach between the two planets in recorded history. *

Great oppositions, as we will call these, occur once every decade or so.
Its not too rare… the opposition of mars occurs about once in every two
years, which is a close approach between earth and mars. The word
“opposition” comes from the fact that on that day, the earth, sun and mars
are almost in a stright line, so the sun and mars are opposite to each
other in the sky on that day. But neither the orbit of earth nor mars is
circular, so the distance between the two planets may be different on each
of these approaches. Once a decade or so, it is closer than most
approaches – this is called a “great opposition”. The last one happened in
2003, if i remember the date right.

> *The next time Mars may come this close is in 2287. Due to the way
> Jupiter’s
> gravity tugs on Mars and perturbs its orbit, astronomers can only be
> certain
> that Mars has not come this close to Earth in the last 5,000 years, but it
> may be as long as 60,000 years before it happens again. *

contradiction ! If astronomers are not sure of orbit as the mail claims
here, then where did the number 2287 come from ?

fact : astronomers do very detailed observations of planets, and the
orbits of planets can be calculated with great accuracy over enormous
periods of time. It is true that the gravity of jupiter perturbs orbits,
but that effect is well measured and well predictable for all the major
planets. Hence, we know exactly where mars will be, on any given date and
time.

> *The encounter will culminate on **August 27th when Mars comes to within
> 34,649,589 miles of Earth and will be (next to the moon) the brightest

error !
the opposition of mars in 2005 is in november, not august. see for example
http://www.tnni.net/~dustymars/Article_2005.htm
the site explains clearly how the 2003 approach was closer than the 2005
approach of mars.

> object in the night sky. It will attain a magnitude of -2.9 and will
> appear
> 25.11 arc seconds wide. By August 27, Mars will look as large as the full

error !
the quoted angular diameter of mars is not true for ANY date this year.
This can be verified from numersous astronomy software. for a simple, free
software usable online as well as offline, see http://www.fourmilab.ch/yoursky
(or download “home planet” from the same site)

> moon to the naked eye. Mars will be easy to spot.*

contradiction !
the moon subtends an angular diameter of about 30′ (called 30 arc minutes)
in the sky, which is 0.5 degrees. The quoted angular diameter of mars is
29″ (29 arc seconds, i.e 29/60 arc minutes, or about 0.01 degrees. thats
60 times smaller than the moon.
And of course, the true diameter of mars at oppositions this year is about
20 arc seconds, or 90 times smaller than the moon !

> *At the beginning of August it will rise in the east at 10p.m. and reach
> its
> azimuth at about 3 a.m. by the end of August when the two planets are
> closest, Mars will rise at nightfall and reach its highest point in the
> sky

contradiction !
the opposition of mars this year is in early november, not august. Only in
late october – early november 2005 will you see mars overhead at midnight.
in other times in 2005, it ill be overhead at other times – NOT midnight.

> at 12: 30a.m. That’s pretty convenient to see something that no human
> being
> has seen in recorded history. So, mark your calendar at the beginning of
> August to see Mars grow progressively*
> *brighter and brighter throughout the month.*

mars will keep becoming brighter, true, but it will become brightest in
late oct / early november, not in august. If you are lucky to have clear
skies, you can go out and look for yourself !

closest to earth in a few centuries or not, the beautiful red neighbour of
earth is always a good sight to see !

This forward even made it to the newspapers! Gujarat Samachar had carried it on its front page. I came to know about this thanks to this email. Some sense prevailed with the newspaper publishing an apology later on. This goes to show the level of science reporting in the country.The correct info is just a click away and yet ..

If you want to know the truth about what mars is doing this year, go here.

update : I am getting 3/4 hits from google for this particular post with pple searching for “mars as big as moon” and so on. Irrespective of whether these people believe this or not..the fact seems to be that this email is very popular ..so I appeal to u pple that u send a clarification to who ever sent you the original ‘wrong’ email. Also, good old BadAstronomy has a post on this.

Read Full Post »

A ‘yes’ would truly seem epoch making. But in reality .. this really isn’t a question of scientific worth. Mercury, Venus, Mars, Jup and Saturn were known for a long time. Hershel discovered Uranus in the 1700s, JG Galle discovered Neptune after a few had predicted the existence of such a planet thro calculations and CW Tombaugh added Pluto to the list in 1930. Pluto has been and remains a celestial body with an identity crisis. ..To be (a planet) or not to be?. ‘Planet’ is a loosely defined term with many eminent astronomers having their own views (shape,size,composition,orbit properties are popular criteria). Pluto has had its own opponents, but has made its way to our School Text Books as the ninth planet. And the rest of the eight fellows.. they are in better placed…. They are all BIG..by pluto’s standards.(alright…i know mercury is small.. but it is part of the old ‘planet’ listing… enrolled much before we started measuring sizes and distances!) . Mike Brown puts down this bigginess condition in a scientific way here.(he lists other conditions too). This debate, however, was not very prominent in the public domain. For the layman..we have always had nine planets.(Brown’s page was made for Sedna)

The debate was pushed into public glare last year following the discovery of Sedna by Brown and his team.(see press release) Brown categorically rejected the possibility of Sedna being called a planet. Now, with the yet to be christened 2003 EL61(the object touted as the tenth planet these days), the debate is back in focus. The discovery was announced by Brown (again!) and his team and this time around..they apparently insisted on it being called a Planet. There is a lot of confusion surrounding this discovery. The number of interesting objects actually discovered and the nature of the press releases are being speculated by various pple on the internet. But even assuming that all is fine with the discovery and if we indeed have an object of the claimed size ….do we call it a planet?

It is important to realise that with modern telescopes , vast and unexplored regions of our cosmic neighbourhood are now accessible to us. So, new discoveries are bound to be made. Ofcourse, we will cheer them whenever they are made. Sedna and this latest discovery fall in this domain and full marks to Brown and his team for their fantastic job. Such discoveries require great patience and meticulous observations. More will probably follow.These are times when even graduate text-books get left behind by new discoveries(Observational Astronomy never had it better!). We will understand more about the new objects in terms of their sizes, orbit, composition etc in the future. Though we may not know these things to a great accuracy, these are well defined attribites.. ie when I ask “What is the diameter of Sedna?”.. there is no inherent ambiguity in the question. On the other hand, “Is xxx a Planet?” is an ill-posed question and a yes/no answer may not always be possible. It is time school text books are rewritten.. agreed. But not with an extra planet…. but with a clarification that there is nothing exact about something being a ‘planet’.Much remains to be understood about ‘Planet’ formation and there is no fundamental reason for us to pre-suppose the size range in which ’round’ objects revolving around the sun fall. Lets us treat these discoveries for what they are .. path-breaking advances into a previously unknow zone and avoid this rant about things being ‘called’ a planet. This isn’t a debate of worth!


Read Full Post »