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VY Canis Majoris (VY Cma/ HIP 35793) 4 Mei 2010

Posted by azmirul in Astronomy.
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VY Canis Majoris (VY CMa / HIP 35793) adalah bintang terbesar yang diketahui setakat ini. Di manakah bintang ini. Jika kita melihat buruj Canis Major, ianya hanyalah satu dot kecil sahaja:

http://en.wikipedia.org/wiki/VY_Canis_Majoris

Saiz Matahari berbanding Vy Cma

Saiz matahari yang kelihatan terlalu kecil berbanding VY Canis Majoris (Source: Wikipedia)

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1. Daddy - 4 April 2012

Thks for yr interesting site about astronomy. I was looking to locate
VY CMa in the Canis Majoris Constellation and yu are the only one
to let me know by the picture above .I live in France and i was wondering if there is a way to see this big star or is it only for professional astronomers. U may know ? Why the letters VY? What do they mean? If this star is so big why we cant see it ? thks

Balas
azmirul - 5 April 2012

“VY” letters is referred to naming style of variable star.. for example Sirius (another infamous star in Canis Major constellation) is called Alpha Canis Majoris with designation Alpha CMa (α CMa).. you probably can see VY CMa but not with naked eye (7th-magnitude star is too faint to naked eye).. of course it also depends on your location & sky condition.. to see it yes but to actually locate and identify it is not that easy due to many closer star.. you need a star map with good coordination to identify it.. honestly speaking, i haven’t yet seen (“locate/identify”) it through my telescope.. haha.. embarrassed to admit it, but it’s true.. 🙂

http://en.wikipedia.org/wiki/Variable_star_designation

Variable stars are named using a variation on the Bayer designation format of an identifying label (as described below) combined with the Latin genitive of the name of the constellation in which the star lies

http://en.wikipedia.org/wiki/Bayer_designation

A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation’s Latin name. The original list of Bayer designations contained 1,564 stars.

Most of the brighter stars were assigned their first systematic names by the German astronomer Johann Bayer in 1603, in his star atlas Uranometria (named after Urania, the Greek Muse of Astronomy, along with Uranus, the Greek god of the sky and heavens). Bayer assigned a lower-case Greek letter, such as alpha (α), beta (β), gamma (γ), etc., to each star he catalogued, combined with the Latin name of the star’s parent constellation in genitive (possessive) form. (See List of constellations for the genitive forms.) For example, Aldebaran is designated α Tauri (pronounced Alpha Tauri), which means “Alpha of the Bull”. (The letters of the Greek alphabet were used in antiquity as numerals, so Bayer’s scheme might be regarded as a numbering system.)

Variable Star Naming
http://www.stellar-database.com/variable.html

Variable stars are those stars that change their apparent brightness (or sometimes their color) over time. They are unusual enough to have their names more well-coordinated within the astronomical community than “normal” stars. Unfortunately, for historical reasons, the naming scheme is more complicated than it needs to be. The first variable star to be discovered in a constellation, if it doesn’t already have a Greek-letter name or a Flamsteed number, is called R followed by the genitive name of the constellation; thus, the first variable star discovered in the constellation of Cetus that didn’t already have a Bayer or Flamsteed designation was named R Ceti. The second variable star discovered in that constellation is called S, the third T, then U, then V, then W, then X, then Y, and then Z. This covers the first nine variable stars discovered in any given constellation.

The tenth variable star to be discovered in a constellation is named RR. (RR Lyrae is a famous example among astrophysicists.) The next is called RS, then RT, then RU, then RV, then RW, then RX, then RY, then RZ. The next variable found after RZ is called SS, then the next ST, etc., through SZ; then TT through TZ, then UU through UZ, then VV through VZ, then WW through WZ, then XX through XZ, then YY, then YZ, and finally ZZ. This covers everything up through the 54th variable star discovered in that constellation.

What does VY mean in VY Canis Majoris?
http://answers.yahoo.com/question/index?qid=20100907160609AAV6MPm

Variable stars inside a constellation boundary, like Canis Major, are given a prefix to distinguish them from regular, constant stars, like Alpha Canis Major (Sirius). The Roman alphabet is used, and if not enough letters available, two letters are used.

Can you see the red hypergiant VY Canis Majoris in the night sky?
http://answers.yahoo.com/question/index?qid=20100104101355AADSuXD

Would I be able too see VY Canis Majoris well with a 3 inch refractor in light-polluted skies?
http://uk.answers.yahoo.com/question/index?qid=20110507122342AAwZD7J

Another star map for VY CMa for your reference:
http://www.aavso.org/cgi-bin/vsp.pl?action=render&name=vy+cma&ra=&dec=&charttitle=VY+CMa&chartcomment=&aavsoscale=Choose&fov=900&resolution=100&maglimit=9&north=up&east=left&othervars=&chartid=2562awv&Submit=Plot+Chart

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