Astronomy

Which star with a Bayer designation is the farthest from the Sun?

Which star with a Bayer designation is the farthest from the Sun?

The key to finding the answer seems to involve processing data from astronomical databases, which I'm not sure how to do in this case. I'd prefer to limit the answer to the original list of approximately 1500 stars, but answers that rely on a list that contains stars with more recently acquired designations could be interesting to consider as well.


See important caveat to this answer below

At a distance of 2992 light years, Tau Canis Major is the furthest of the 1513 stars that have a Bayer designation, with several others almost equally distant. I computed the full list of Bayer-Sun distances: https://github.com/barrycarter/bcapps/blob/master/ASTRO/bc-bayer-distance.csv

Important Caveat

I used the HYG catalog at https://github.com/astronexus/HYG-Database but it may be inaccurate. In particular, Wikipedia gives Tau Canis Major's distance as 5,000 light years, although I couldn't find this number in the source provided (https://doi.org/10.1088/0067-0049/199/1/8), although I only skimmed.

The far from canonical https://www.universeguide.com/star/taucanismajoris notes that 2992.32 is a revised figure, down from 3197.68, but, of course, the figure may have been revised again.

Methodology

After downloading the HYG database file, this one liner creates bc-bayer-distance.csv:

zcat hygdata_v3.csv.gz | perl -F, -anle 'if ($F[9] < 100000 && length($F[27])>0) {$F[9] *= 3.26156; print "$F[9], $F[27] $F[29]"}' | sort -nr | tee bc-bayer-distance.csv

A brief explanation:

  • The 9th field (starting our count with 0 as Perl does) is the distance, but there's a note on the HYG git page: "A value >= 10000000 indicates missing or dubious (e.g., negative) parallax data in Hipparcos". It turns out the actual number is 100,000 (I've submitted a correction), so we ignore distances greater than 100,000.

  • The distance is in parsecs, so I multiply by 3.26156 to convert to light years.

  • The 27th field is the stars Bayer letter designation without the constellation. If it's empty, we ignore the star.

  • The 29th field is the stars constellation name, which, combined with 27th field, yields the Bayer designation.


Celestial Observation

On star maps, brighter stars appear as a larger dot and smaller stars as a smaller dot.

Stars are labelled according to their brightness. The system that astronomers use is the Bayer Designation, named after the German astronomer Johann Bayer who in 1603 catalogued stars by using the Greek alphabet to represent their brightness where Alpha is the brightest, Beta the next brightest etc.

With this system the brightest star in Orion is Alpha Orionis.

When Bayer had used all the 24 letters he started using lower case Latin letters (our alphabet).

It is in use today but has been amended over time by the International Astronomy Union.

Some criticism of the system is that it does not take into account changes in the brightness of stars due to variability or that the Alpha star is sometimes not the brightest star. Changes in constellation boundaries have led to some confusion. The top right star of the square of Pegasus is Alpha Andromedae.

Amongst other ways to label stars are Flamsteed numbers which number stars by their brightness.


Bayer designations in Orion

Bayer
Designation
Apparent
Magnitude
Proper
Name
α Ori 0.45 Betelgeuse
β Ori 0.18 Rigel
γ Ori 1.64 Bellatrix
δ Ori 2.23 Mintaka
ε Ori 1.69 Alnilam
ζ Ori 1.70 Alnitak

Orion provides a good example of Bayer's method. Bayer first designated Betelgeuse and Rigel, the two 1st-magnitude stars (those of magnitude 1.5 or less), as Alpha and Beta from north to south, with Betelgeuse (the shoulder) coming ahead of Rigel (the foot), even though the latter is usually the brighter. (Betelgeuse is a variable star and can at its maximum occasionally outshine Rigel.) [5] Bayer then repeated the procedure for the stars of the 2nd magnitude (those between magnitudes 1.51 and 2.5), labeling them from gamma through zeta in "top-down" (north-to-south) order.


Which star with a Bayer designation is the farthest from the Sun? - Astronomy

Each of you has your very own star. By the end of this exam, you be an Astronomy 101U/V expert on that one star. I expect your work to be complete, accurate, and above all, representative of your best effort. Answer all questions as specifically as possible. Most answers should involve only a few, succinct sentences you do not have room for much verbal rambling. Supply all information in the spaces provided on these sheets. Please make sure I can easily read your writing otherwise, I will assume you really didn't want me to.

In some cases, you will have to estimate some qualities or quantities for your star. (For example, you cannot find any definite information about the evolutionary stage of your star. Would a star of exact or similar spectral type and luminosity class do as a reference?) As is the case for the labs this quarter, just make sure that you spell out the logic you used. Original and/or sound reasoning is just as important as getting the "right" answer. You may find conflicting values for your star in the sources you use. Please reference all sources in your work .

Links

References

  • Burnham's Celestial Handbook (Physics-Astronomy library, 6th floor C wing)
  • Various figures, tables, graphs, and text in the chapters assigned
  • Lab exercises and activities
  • The Naming of Stars

Equations

  • Figures 6.4, 6.10, 6.23, 13.9, 13.10, 14.6 (brief edition)
  • Figures 7.5, 7.12, S2.18, 15.1, 15.12, 16.6, 16.8 ("big book")
  • Plus others
    You are welcome to use the figures in your text to get approximate values for the answers to some of the questions. If you want a more accurate answer, it is better to use an equation:

Questions

Identifying Your Star

Stellar Parameters (8 pts)

(Note: when you see "magnitude" in your references, that means apparent magnitude .

Star Name Bayer
Designation
Surface
Temperature
Spectral
Type
Luminosity
Class
Apparent
Magnitude
Absolute
Magnitude
Distance
(Parsecs)

Observing your Star

  1. (2 pts) Which season would be the best one for observing your star? (Pick the one where it is in the night sky for the most hours -- your text has star maps.)

The Evolution of Your Star

  1. Fill in the life track of a 1 solar-mass star from main sequence to red-giant stage.
  2. Do the same for a 3 solar-mass star and a 6 solar-mass star assuming the evolution off of the main sequence retraces their birth path to the main sequence (Fig. 14.8).
  3. Using the spectral type and luminosity class of your star, locate your star on this graph.
  4. What is the mass of your star? (Give your source or how you figured out the mass.)

    (2 pts) Approximately how long did (will) your star spend on the main sequence? (Show all work or reference the figure used.)


Properties [ edit | edit source ]

Sigma Draconis is a main sequence dwarf which has long served as a K0 V spectral standard star. Its classification as K0 V defines one of the anchor points of the Morgan–Keenan system that have remained unchanged since the original 1943 MKK Atlas. However, some modern spectroscopy gives it as designation of G9 V.

The radius of Sigma Draconis has been directly measured using interferometry with the CHARA array, which yields a result of 77.6% of the Sun's radius. It has 85% of the Sun's mass, but the luminosity of this star is only 41% that of the Sun. The projected rotation rate (v sin i) is relatively low at 1.4 km/s. It is considered a slightly metal-poor star, meaning that it has a lower proportion of elements with masses greater than helium when compared to the Sun.

The temperature, luminosity and surface activity appear to vary slightly in a manner very similar to the sunspot cycle, although the full length of the cycle has not yet been determined (as of 1992). The total variability is among the lowest of all stars that have been measured by the Hipparcos spacecraft.

Sigma Draconis has a high proper motion, advancing across the celestial sphere at a rate of 1.835 arc seconds per year. The star made its perihelion passage about 46,725 years ago, when it came within 16.55 ly (5.075 pc). The components of Sigma Draconis's space velocity are U=+36, V=+40 and W=-10 km/s. This gives the star an unusually large orbital eccentricity about the Milky Way galaxy of 0.30 (compared to 0.06 for the Sun.) The mean galactocentric distance for the orbit is 10.3 kiloparsecs (about 34,000 light-years).

As of 2013, no Jupiter-size or larger companion had been detected about the star and there was no indication of excess infrared radiation that would be evidence of circumstellar matter (such as a debris disk).


Pointers

Some Pointers on Using Laser Pointers
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Constant Contact Use.

Dubhe and Merak (Alpha and Beta Ursae Majoris), the two stars at the end of the bowl of the Big Dipper are habitually called The Pointers:[15] a line from β to α and continued for a bit over five times the distance between them, .

In some cases the pointers consisted of little pictorial icons called zoomorphs representing the star they pointed to.

Leading the westward moving parade are Dubhe at the lip of the Dipper's bowl and Merak, also at the bowl's front and just to the south of Dubhe, the two making the Big Dipper's "

It has a useful diagram showing the relative brightness and distance of the stars in Crux and the

. It is part of an excellent Australian educational site Astronomy on the Net that also includes monthly sky charts.

Several stories of Crux emerge from different Indigenous groups in Victoria, with the

(&alpha and &beta Centauri) signifying brothers for many people including the Wotjobaluk, Kurnai, Ya-itma-thang and Kurnai. For the Wotjobaluk, these brothers are known as Bram Brambult.

Please note that these laser

should be handled responsibly. It is legal to operate the devices the U.S. provided you don't try anything dumb, like shining one at an aircraft in flight.

Around the same time (c.1640), he invented the eyepiece micrometer, in which a precision screw was used to move two

#general is used for wiki-related chat, #random is for off-topic chat, #server-suggestions is to suggest changes to this Discord server #editing is for help and hints on editing, and #coding-help is for people who need

on templates, HTML, JavaScript, CSS, and Lua.
Please keep your username recognizable.

- The Antikythera Mechanism is made up of a complex network of dials,

and other minute features. The cover of the mechanism included a number of markings that have been identified as representing the Sun and planets and the 76-year 'Kallippic' calendrical cycle.

You can find the Square of Pegasus by following the line from the

of the Big Dipper through Polaris and then twice as far on Polaris' other side. One of the stars (Alpheratz) is actually now over the boundary into the constellation Andromeda. The other three stars are in Pegasus.

They appear as a single star, known as Alpha Centauri AB, which is the third brightest star in the night sky, the brighter of the two

(which point to the Southern Cross). They can be resolved into two separate stars with a small telescope or good binoculars.

The two stars also serve as

to the Southern Cross, which lies under the centaur's rear legs.
MAJOR STARS IN CENTAURUS
Rigil Kentaurus - α Centauri (Alpha Centauri) .

function in Unix, because inter-file

don't work when mapping files into semi-arbitrary places. Multics had such addressing mode built into most instructions. In other words it could perform relocated inter-segment references, thus eliminating the need for a linker .

Some technologies were developed by transapients who then either gave them directly to modosophonts as gift technologies, or gave them

, guidance or simply vague hints which allowed the modos to invent the technology in question independently.

Although it has the Bayer designation "beta", it is the 5th brightest and not the second brightest star in Ursa Major. Merak is the southern-most of the

, the two stars of Ursa Major which point towards the Pole Star.

At first these charts can seem a bit confusing but by picking out one or two of the more familiar constellations you can use these as

to other constellations.
If you are viewing from the northern hemisphere one of the best places to start is with the Plough.

Polaris can be located by following the line upward from the two stars (the

) at the right end of the bowl of the Big Dipper or, if the Big Dipper is not visible, by following the line through the left side of the square in Pegasus through the end star in Cassiopeia.

If you want to test yourself sometime, go outside on a clear night and look north. Find the Big Dipper, and use its "

" to locate the Little Dipper.

The two brightest stars in the constellation are Dubhe and Merak (&alpha and &beta Ursa Majoris), also known as the

because a line drawn through them points to Polaris, the North Star. The main objects of amateur astronomical interest in Ursa Major are galaxies, five of which have Messier numbers.

Down south we find the southern celestial pole roughly at the intersection of a line drawn out from the long axis of the Southern Cross and another line drawn perpendicular to the mid point of the "

" (an asterism of Alpha and Beta Centauri) - above the southern horizon
Reply
Chew says: .

After you locate the dipper, look at the two stars that mark the outer edge of its bowl. Now connect these two stars, then extend the line above the dipper's bowl. Polaris, the north star, lies along this line, about five times the distance between the two

It's from Sunday's Guardian. The article rightly says that Capricornus is an important constellation because it is part of the ancient zodiac, but it is inconspicuous, and you can at present use Jupiter and Saturn as

to it.
Chart via The Guardian.

Southern Hemisphere, I initially struggled to orient myself under the new celestial tapestry - and the sheer number of stars visible without significant light pollution didn't help me get my bearings. Fortunately, the stars Alpha and Beta Centauri are fantastically easy to spot. Aptly nicknamed "The Southern

The ones that do are also visible from the more southern parts of the northern hemisphere. The False Cross is not a part of a constellation, and the Southern Cross is another name for Crux. The Three Patriarchs is also known as Triangulum Australe. The Southern

Bright star was visible at 48x East of its bright and broad nucleus. Finally, at 11:26pm, I reached the last Messier member of Virgo "family" by following "

" above Corvus. The bright spindle of M104 as well as its dark dust lane were clearly visible at 48x.

: Two or more stars in a constellation that show the way to another constellation.
Pole : One of the two points on a planet's surface that are farthest away from its equator.
Primary star : The brighter star in an eclipsing variable
Prominence : A cloud of gas that bursts out from the Sun's surface.


Star names and designations

Of approximately 5,000 stars visible to the unaided eye, only a few hundred have proper names, and fewer than 60 are commonly used by navigators or astronomers. A few names come almost directly from the Greek, such as Procyon, Canopus, and Antares—the latter derived from “anti-Ares” or “rival of Mars” because of its conspicuous red colour. The stars Sirius (“Scorcher”) and Arcturus (“Bear Watcher”) are mentioned by both Homer and Hesiod (8th century bce ?). Aratus names those two as well as Procyon (“Forerunner of the Dog”), Stachys (“Ear of Corn”?, now Spica), and Protrugater (“Herald of the Vintage,” now Latinized to Vindemiatrix).

The Al that begins numerous star names indicates their Arabic origin, al being the Arabic definite article “the”: Aldebaran (“the Follower”), Algenib (“the Side”), Alhague (“the Serpent Bearer”), and Algol (“the Demon”). A conspicuous exception is Albireo in Cygnus, possibly a corruption of the words ab ireo in the first Latin edition of the Almagest in 1515. Most star names are in fact Arabic and are frequently derived from translations of the Greek descriptions. The stars of Orion illustrate the various derivations: Rigel, from rijl al-Jawzah, “Leg of Orion,” Mintaka, the “Belt,” and Saiph, the “Sword,” all follow the Ptolemaic figure Betelgeuse, from yad al-Jawzah, is an alternative non-Ptolemaic description meaning “hand of Orion” and Bellatrix, meaning “Female Warrior,” either is a free Latin translation of an independent Arabic title, al-najid, “the conqueror,” or is a modification of an alternative name for Orion himself. Only a handful of names have recent origins—for example, Cor Caroli (Latin: “Heart of Charles”), the brightest star in Canes Venatici, named in 1660 by Sir Charles Scarborough after the executed English king Charles I.

Bayer’s Uranometria of 1603 introduced a system of Greek letters for designating the principal naked-eye stars. In this scheme, the Greek letter is followed by the genitive form of the constellation name, so alpha (α) of Canes Venatici is Alpha Canum Venaticorum. Bayer’s letters and their extension to newer constellations apply to about 1,300 stars. In Historia Coelestis Britannica (published posthumously in 1725), Flamsteed numbered the stars within each of 54 constellations consecutively according to right ascension, and the Flamsteed numbers are customarily used for the fainter naked-eye stars such as 61 Cygni.

An astronomer wishing to specify an even fainter star will usually take recourse to a more extensive or more specialized catalog. Such catalogs generally ignore constellations and list all stars by right ascension. Thus, astronomers learn to recognize that BD +38°3238 refers to a star in the Bonner Durchmusterung and that HD 172167 designates one in the Henry Draper Catalogue of spectral classifications in this case, both numbers refer to the same bright star, Vega (Alpha Lyrae). Vega can also be specified as GC 25466, from Benjamin Boss’s General Catalogue of 33,342 Stars (1937), or as ADS 11510, from Robert Grant Aitken’s New General Catalogue of Double Stars (1932). These are the most widely used numbering systems. For more obscure names, such as Ross 614 or Lalande 21185, most astronomers would have to consult a bibliographical aid to discover the original listing.

Variable stars have their own nomenclature, which takes precedence over designations from more specialized catalogs. Variable stars are named in order of discovery within each constellation by the letter R to Z (providing they do not already have a Greek letter). After Z the double from RR to RZ, SS to SZ,…is used after ZZ come the letters AA to AZ, BB to BZ, and so on, the letter J being omitted. After the letters QX, QY, and QZ, the names V335, V336, and so on are assigned. Hence, the first lettered variable in Cygnus is R Cygni, and the list reached V2491 by 2010. The names were assigned by the Soviet authors of the General Catalogue of Variable Stars (3rd edition, 1969), with the approval of the Commission on Variable Stars of the International Astronomical Union.

Two catalogs are frequently used for designating star clusters, nebulas, or galaxies. The shorter list of these, which includes 110 of the brighter objects, was compiled in three installments by the French astronomer Charles Messier in the latter part of the 18th century M1 and M31 are examples of this system, being, respectively, the Crab Nebula and the great galaxy in Andromeda. A much more extensive tabulation in order of right ascension is the New General Catalogue ( NGC 1890), followed by the Index Catalogue ( IC 1895, 1908) examples are NGC 7009 or IC 1613.


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  • Stars named with a Bayer, Flamsteed, HR, or Draper (not from the supplements) designation.
  • Stellar extremes or otherwise noteworthy stars.
  • Notable variable stars (prototypes, rare or otherwise important).
  • Nearest stars (<20 ly).
  • Stars with planets.
  • Notable neutron stars, black holes, and other exotic stellar objects/remnants.

Note that these lists are currently unfinished, and there may be stars missing that satisfy these conditions. If you come across one, please feel free to add it.


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