Star categories

I've noticed that stars are classified with letters of the alphabet.
This story
http://www.spaceref.com/news/viewpr.html?pid=18792
for example mentions "K stars" and "F stars". I'm wondering if this
system has a name. A Google search for "star categories" turned up
nothing useful.

Tom Rauschenbach wrote:
I've noticed that stars are classified with letters of the alphabet.
This story
http://www.spaceref.com/news/viewpr.html?pid=18792
for example mentions "K stars" and "F stars". I'm wondering if this
system has a name. A Google search for "star categories" turned up
nothing useful.

Try this thread:

http://groups.google.com/group/sci.p...51c086c10e6092

Jerry

On Sat, 21 Jan 2006 11:08:58 -0500, Tom Rauschenbach
wrote:



I've noticed that stars are classified with letters of the alphabet.
This story
http://www.spaceref.com/news/viewpr.html?pid=18792
for example mentions "K stars" and "F stars". I'm wondering if this
system has a name. A Google search for "star categories" turned up
nothing useful.

Google for The Harvard Spectral Sequence

OBAFGKMRNS

--
Tom Hise - NCØO
N42° 06' 41" - W91° 52' 59"

Tom Rauschenbach wrote:

I've noticed that stars are classified with letters of the alphabet.
This story
http://www.spaceref.com/news/viewpr.html?pid=18792
for example mentions "K stars" and "F stars". I'm wondering if this
system has a name. A Google search for "star categories" turned up
nothing useful.



Some where I have read about the origin of the seven spectral
classes O-B-A F-G-K-M, but cant locate it... but I did find some
good links...


Harvard Spectral Class sequence for Stars

http://www.physics.sfasu.edu/astro/a...inks/all5.html

http://csep10.phys.utk.edu/astr162/lect/index.html
http://csep10.phys.utk.edu/astr162/l...s/harvard.html


http://history.nasa.gov/CP-2156/glossary.htm

spectral type (or class) - classification used to sort stars by
photospheric temperature and intrinsic brightness. The seven spectral
classes O-B-A F-G-K-M, listed in order of decreasing temperature,
include 99% of all known stars. Each spectral type is divided into a
variable number of subtypes designated by Arabic numerals. Further,
stars are sorted by intrinsic brightness into luminosity classes
designated by the first five Roman numerals. In turn, these are
subdivided into a small number of subclasses designated by the first
few letters of the lower case English alphabet; for example, the Sun
is a G2 V star (also sometimes denoted as a dwarf G2 star) and
Betelgeuse (Greek letter alpha Orionis) is classified as M2 lab
(i.e., intermediate between la and lb)

Tom Rauschenbach wrote:
I've noticed that stars are classified with letters of the alphabet.
This story
http://www.spaceref.com/news/viewpr.html?pid=18792
for example mentions "K stars" and "F stars". I'm wondering if this
system has a name. A Google search for "star categories" turned up
nothing useful.

I teach university classes about this topic every now and then.
You might look at some of my notes.

Introductory version:

http://spiff.rit.edu/classes/phys230...ec_interp.html

Intermediate version:

http://spiff.rit.edu/classes/phys301...ass/class.html

More advanced version:

http://spiff.rit.edu/classes/phys440...o_spectra.html
http://spiff.rit.edu/classes/phys440...pec_class.html

There are links to further information in these pages.

Michael Richmond

On Sat, 21 Jan 2006 11:08:58 -0500, Tom Rauschenbach
wrote:



I've noticed that stars are classified with letters of the alphabet.
This story
http://www.spaceref.com/news/viewpr.html?pid=18792
for example mentions "K stars" and "F stars". I'm wondering if this
system has a name. A Google search for "star categories" turned up
nothing useful.


Google for "Herzsprung-Russel Diagram" instead or try:

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

Nick


--
Nick Theodorakis

contact form:
http://theodorakis.net/contact.html

Tom Hise wrote:
On Sat, 21 Jan 2006 11:08:58 -0500, Tom Rauschenbach
wrote:

Google for The Harvard Spectral Sequence

OBAFGKMRNS

Hi:

Alas...the "RNS" designations have been superceded now (largely by
"C"). It's a shame, because I used to be able to teach my students the
mnemonic:

"Oh Be A Fine Girl, Kiss Me Right Now Smack."

Always being careful to _also_ tell them Miss Dorothy's favorite:

"Only Boys Accepting Feminism Get Kissed Meaningfully."

:-)

Peace,
Rod Mollise
Author of _Choosing and Using a Schmidt Cassegrain Telescope_
Like SCTs and MCTs?
Join the SCT User Mailing List.
http://www.groups.yahoo.com/group/sct-user
============================
See my home page at
http://skywatch.brainiac.com/astroland/index.htm
for further details!
============================
For Uncle Rod's Astro Blog See:
http://journals.aol.com/rmollise/UncleRodsAstroBlog/

On 21 Jan 2006 10:33:23 -0800, "RMOLLISE" wrote:

Alas...the "RNS" designations have been superceded now (largely by
"C"). It's a shame, because I used to be able to teach my students the
mnemonic:

"Oh Be A Fine Girl, Kiss Me Right Now Smack."

Always being careful to _also_ tell them Miss Dorothy's favorite:

"Only Boys Accepting Feminism Get Kissed Meaningfully."

You can tell how long it's been since I took an astronomy class.

The mnemonic I learned from W. P. Bidelman was: "Oh Be A Fine Girl, Kiss Me
Right Now Sugar"


--
Tom Hise - NCØO
N42° 06' 41" - W91° 52' 59"

"Tom Rauschenbach" wrote in message
news


I've noticed that stars are classified with letters of the alphabet.
This story
http://www.spaceref.com/news/viewpr.html?pid=18792
for example mentions "K stars" and "F stars". I'm wondering if this
system has a name. A Google search for "star categories" turned up
nothing useful.


You might find Jim Kaler's website interesting. Enter here for more infor on
spectral classification

http://www.astro.uiuc.edu/~kaler/sow...a.html#classes

----------------------------------------------------------------------------
-
Robin Leadbeater
54.75N 3.24W
http://www.leadbeaterhome.fsnet.co.uk/astro.htm
----------------------------------------------------------------------------
-

Tom Rauschenbach wrote in
news


I've noticed that stars are classified with letters of the alphabet.
This story
http://www.spaceref.com/news/viewpr.html?pid=18792
for example mentions "K stars" and "F stars". I'm wondering if this
system has a name. A Google search for "star categories" turned up
nothing useful.



http://physics.pdx.edu/telescope/site5/hr.html