This poster for the Natural Sciences Poster Session at Parkland College features the constellation Gemini, including a calculation of the change in rise time to determine the length of a year, determining the life span of the major stars in the constellation, identifying Messier objects within the region as well as the mythology behind the name of the constellation

Dalton, Michael

English

SPARK: Scholarship at Parkland | Parkland College

Parkland College
Natural Sciences Poster Sessions Student Works
2019
Gemini
Michael Dalton
Parkland College
Open access to this Poster is brought to you by Parkland College's institutional repository, SPARK: Scholarship at Parkland. For more information,
please contact spark@parkland.edu.
Recommended Citation
Dalton, Michael, "Gemini" (2019). Natural Sciences Poster Sessions. 162.
https://spark.parkland.edu/nsps/162
Project Part 2 Graph
0
A
lti
tu
de
 (°
)
5
10
15
20
25
30
35
40
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50
Azimuth (°)
265 270 275 280 285 290 295
Michael Dalton | AST 102 | Spring 2019
τ Gemini
Alzirr
Tejat
κ Gemini
Mekbuda
Mebsuta
Wasat
Alhena
Pollux Castor
(280, 25)
141 light years
34 light years
321 light years
845 light years
52 light years
60 light years
1376 light years
109 light years
232 light years
59 light years
GEMINI
Introduction
In this project from Astronomy 102, I selected Gemini as the constellation to study. I observed the 
constellationʼs position in the sky based on information Iʼve learned in Astronomy 102. Gemini is 
most notable for the two bright stars, Castor and Pollux, that make up the heads of the twins in 
Gemini. The end goal is to determine their age and fate.
Relationship of Stars
Although the distance between stars appears close in our night sky, they arenʼt located close to 
each other in space. The reason they appear close together is because they have a differing 
amount of luminosity 
and mass. The closer they are to Earth, the greater potential they have for appearing nearby. 
One of the most luminous stars, Mekbuda, is one of the furthest from Earth. It does not appear as 
bright as Castor, a star that is located much closer at 52 light years away and is an A1.5 IV star. 
The grouping of a constellation is based on their brightness that can be observed from Earth. This 
does not necessarily mean they are close together.
Arrangement of Stars
Observation position: Latitude 40° North, Longitude 88° West.
Date: May 23, 2019
Time: 9pm
The constellation of Gemini will feature this exact arrangement of stars in the sky based 
on the information above.
We know the stars in Gemini didnʼt form at the same time 
because they vary greatly in distance and age when compared 
to one another.
M-35, the Shoe Buckle Cluster is located 
approximately 2,800 light years from Earth and was 
discovered in 1764. (Gemini Constellations)
IC 443, the Jellyﬁsh Nebula is located 
approximately 5,000 light years from Earth. The first 
sighting was in 1892 by Max Wolf and was later 
confirmed by E.E. Barnard. (Frommert, Hartmut)
Deep Sky Objects
The only Messier object in Gemini is M-35, 
which is the Shoe Buckle Cluster. If this 
region of the sky were observed with a 
research-grade telescope, you could expect 
to see more objects than the number 
catalogued by Charles Messier in the 18th 
century. The reason for this is that the M35 
cluster is very large and modern telescopes 
are able to see much dimmer objects than 
previously possible. This is because there 
have been numerous technological advances 
over the centuries, improving our ability to 
observe the sky through telescopes.
Poster by: Michael Dalton
Star Name Spectral Type Luminosity Class Mass Main Sequence Lifetime (years) Completed Lifetime (years) Remaining Lifetime Death Order Fate of Stellar Core
Castor A1.5 IV 4.7 462,000,000 462,000,000 46,200,000 5 White Dwarf
Pollux G9 III 2.3 1,890,000,000 1,890,000,000 189,000,000 7 White Dwarf
Alhena A1.5 IV 4.7 462,000,000 462,000,000 46,200,000 5 White Dwarf
Wasat F2 V 1.5 4,440,000,000 none 4,890,000,000 10 White Dwarf
Mebsuta G9 Ib 3.8 693,000,000 762,000,000 6,930,000 1 White Dwarf
Mekbuda G1 Ib 2.6 1,480,000,000 1,630,000,000 14,800,000 3 White Dwarf
κ (Kappa) Geminorum G9 III 2.3 1,890,000,000 1,890,000,000 189,000,000 7 White Dwarf
Tejat M3 III 4.8 434,000,000 434,000,000 43,400,000 4 White Dwarf
Alzirr F5 IV-V 2.1 2,270,000,000 2,270,000,000 227,000,000 9 White Dwarf
τ (Tau) Geminorum K2 II 3.4 865,000,000 952,000,000 8,650,000 2 White Dwarf
M-35, Shoe Buckle Cluster — Constellation Guide
The Shoe-Buckle Cluster looks significantly 
dense with small stars compared to the 
surrounding space. The cluster seems to be 
brightest near the center with a hazy yellow 
glow and bright white and yellow spots that 
dim around the edges of the group.
An open star cluster is a group of many stars 
concentrated in a certain area. Open clusters 
form from a giant molecular cloud, so most 
of the stars contained in it are about the 
same age. The stars of the cluster hold 
gravitational pull on each other.
IC 443, the Jellyﬁsh Nebula — Constellation Guide
The Jellyfish Nebula is a supernova remnant. 
It looks like a much larger group of stars with 
a similar density to the Shoe Buckle Clusterʼs 
density with pretty even spacing. Near the 
center of the Jellyfish is a large cloud with 
varying yellow, red and orange portions. The 
brightest part of the cloud is very red and 
yellow. There is very bright star called Propus 
near the outside of the cloud, but still within 
the overall grouping of stars. 
Supernova remnants are the remains of an 
exploded star which went supernova. The 
explosion of the supernova star spreads 
material outward in a shockwave, heating up 
other material nearby.
To determine the length of a year, I began by marking the time that Castor rose above the horizon 
at the start of each week for five weeks. After taking the difference between each consecutive 
week, I divided these numbers by 7 for the number of days in a week. This resulted in a weekly 
average change of rise time for Castor of 3.93 minutes. We were able to estimate the number of 
days in a year at 366.4122 days by dividing the average change of rise time for Castor per day 
(3.93 minutes) by 1,440 minutes (the number of minutes in a given day). The tables above 
illustrate the results of my calculations.
Average change in rise time per day: 3.93
Calculated number of days in a year: 366.4122
Calculated percent error: 0.32%
A possible source of error in my calculations could be from not observing enough rises, there could 
have been greater variance in the rise times from day to day since we only observed and 
recorded each week over four sidereal weeks. Also, this estimation doesnʼt account for time zone 
changes and leap years, so that could also lead to inaccuracies. Given that the result is less than 
1% of an error, using this method to estimate short periods of time would be a fine. However if 
used to calculate longer periods of time this would lead to some pretty big inaccuracies, because it 
doesnʼt account for changes in time zones, leap years, and your changing position on earth.
Date 
Rise Time for Castor (Apollo) 
Hour Minute Second 
May 23 08 19 09 
May 30 07 51 38 
June 6 07 24 06 
June 13 06 56 35 
June 20 06 29 04 
 
     
Change in Rise Time Change in Time 
Decimal Minutes 
Change in Time Per Day 
in minutes/day Hours Minutes Seconds 
5/23–5/30 - 27 31 27.52 3.93 
5/30–6/6 - 27 32 27.53 3.93 
6/6–6/13 - 27 31 27.52 3.93 
6/13–6/20 - 27 31 27.52 3.93 
 
Determing the Length of a Year
Mythology
Gemini is Latin for twins, and the constellation represents the two twin brothers, Castor and 
Pollux. They are the sons of Leda but have two different fathers: her husband, Tyndarus of 
Sparta, and Jupiter, who appeared to her in the form of a swan. Pollux was immortal and 
his brother, Castor, was mortal. Pollux was known for his strength and Castor for his skill 
with horses. They both fought in the Trojan War to bring back their sister, Helena, from 
capture. They typically depicted carrying spears and riding matching horses. The 
mythiological reason for them appearing in the stars is that Pollux was grieving the loss of 
his brother, Castor, and asked his father, Jupiter, to share Polluxʼs immortality with his 
brother, Castor. Because of the heroism displayed by both brothers, Jupiter granted them 
both immortality in the stars (Bell, Cathy).
Works Cited
Bell, Cathy. “The Mythology of the Constellations.” The Mythology of the Constellations,
www.comfychair.org/~cmbell/myth/myth.html. 
“Constellation Guide.” Constellation Guide, 
www.constellation-guide.com/constellation-list/gemini-constellation/.
Frommert, Hartmut. IC 443, spider.seds.org/spider/Misc/i0443.html. 
Gemini Constellation - Facts About Gemini | Solarsystemquick.com, 
www.solarsystemquick.com/universe/gemini-constellation.htm.
Mohon, Lee. “What Spawned the Jellyfish Nebula?” NASA, NASA, 10 Dec. 2015,
www.nasa.gov/mission_pages/chandra/what-spawned-the-jellyfish-nebula.html. 
Castor and Pollux of Gemini — Constellation Guide
Fates of Stars
The following chart illustrates the fates of Castor, Tau Geminorum, and Alzirr. Each 
of these stars will result in a White Dwarf because they will become less than 1.4 
solar masses. Tau Geminorum has the shortest remaining lifetime while Alzirr will go 
on for much longer. Castor overall has the shortest total lifetime 
Name Spectral 
Type 
Luminosity 
Class 
Mass Stages 
Completed 
Completed 
Lifetimes 
Remaining 
Stage 
Remaining 
Lifetimes 
Stellar 
Core 
Fate 
Mass 
Range 
Castor A1.5 IV 4.7 Main 
Sequence 
462,000,000 Red 
Giant, 
Planetary 
Nebula, 
White 
Dwarf 
46,200,000  White 
Dwarf 
Under 
1.4 
solar 
masses 
Tau 
Geminorum 
K2 II 3.4 Main 
Sequence, 
Red Giant 
952,000,000 Super 
Giant, 
Planetary 
Nebula, 
White 
Dwarf 
8,650,000 White 
Dwarf 
Under 
1.4 
solar 
masses 
Alzirr F5 IV-V 2.1 None 2,270,000,000 Main 
Sequence, 
Red 
Giant, 
Planetary 
Nebula, 
White 
Dwarf 
227,000,000 White 
Dwarf 
Under 
1.4 
solar 
masses 
It is possible for a luminosity class III star to have a longer remaining lifetime 
than a class V star because the class III star is not burning through its fuel as 
quickly as a massive class V star. This is because there is generally more 
material contained within the star class V star.  A class III star will not burn 
through its hydrogen fuel as quick as a class V star. The graph below shows 
examples of this point.
All ten of the stars observed end as white dwarfs.
Most stars in the galaxy are less massive than our sun, so it would be a fair 
assumption that anything less than 8 solar masses would become a white dwarf. 
Therefore, I think the fate of my stars are not that far off and that stars that will 
not result in a white dwarf are quite rare.


Gemini

Scholarship at Parkland

Parkland CollegeNatural Sciences Poster Sessions Student Works2019GeminiMichael DaltonParkland CollegeOpen access to this Poster is brought to you by Parkland College's institutional repository, SPARK: Scholarship at Parkland. For more information,please contact spark@parkland.edu.Recommended CitationDalton, Michael, "Gemini" (2019). Natural Sciences Poster Sessions. 162.https://spark.parkland.edu/nsps/162Project Part 2 Graph0Altitude (°)5101520253035404550Azimuth (°)265 270 275 280 285 290 295Michael Dalton | AST 102 | Spring 2019τ GeminiAlzirrTejatκ GeminiMekbudaMebsutaWasatAlhenaPollux Castor(280, 25)141 light years34 light years321 light years845 light years52 light years60 light years1376 light years109 light years232 light years59 light yearsGEMINIIntroductionIn this project from Astronomy 102, I selected Gemini as the constellation to study. I observed the constellationʼs position in the sky based on information Iʼve learned in Astronomy 102. Gemini is most notable for the two bright stars, Castor and Pollux, that make up the heads of the twins in Gemini. The end goal is to determine their age and fate.Relationship of StarsAlthough the distance between stars appears close in our night sky, they arenʼt located close to each other in space. The reason they appear close together is because they have a differing amount of luminosity and mass. The closer they are to Earth, the greater potential they have for appearing nearby. One of the most luminous stars, Mekbuda, is one of the furthest from Earth. It does not appear as bright as Castor, a star that is located much closer at 52 light years away and is an A1.5 IV star. The grouping of a constellation is based on their brightness that can be observed from Earth. This does not necessarily mean they are close together.Arrangement of StarsObservation position: Latitude 40° North, Longitude 88° West.Date: May 23, 2019Time: 9pmThe constellation of Gemini will feature this exact arrangement of stars in the sky based on the information above.We know the stars in Gemini didnʼt form at the same time because they vary greatly in distance and age when compared to one another.M-35, the Shoe Buckle Cluster is located approximately 2,800 light years from Earth and was discovered in 1764. (Gemini Constellations)IC 443, the Jellyﬁsh Nebula is located approximately 5,000 light years from Earth. The first sighting was in 1892 by Max Wolf and was later confirmed by E.E. Barnard. (Frommert, Hartmut)Deep Sky ObjectsThe only Messier object in Gemini is M-35, which is the Shoe Buckle Cluster. If this region of the sky were observed with a research-grade telescope, you could expect to see more objects than the number catalogued by Charles Messier in the 18th century. The reason for this is that the M35 cluster is very large and modern telescopes are able to see much dimmer objects than previously possible. This is because there have been numerous technological advances over the centuries, improving our ability to observe the sky through telescopes.Poster by: Michael DaltonStar Name Spectral Type Luminosity Class Mass Main Sequence Lifetime (years) Completed Lifetime (years) Remaining Lifetime Death Order Fate of Stellar CoreCastor A1.5 IV 4.7 462,000,000 462,000,000 46,200,000 5 White DwarfPollux G9 III 2.3 1,890,000,000 1,890,000,000 189,000,000 7 White DwarfAlhena A1.5 IV 4.7 462,000,000 462,000,000 46,200,000 5 White DwarfWasat F2 V 1.5 4,440,000,000 none 4,890,000,000 10 White DwarfMebsuta G9 Ib 3.8 693,000,000 762,000,000 6,930,000 1 White DwarfMekbuda G1 Ib 2.6 1,480,000,000 1,630,000,000 14,800,000 3 White Dwarfκ (Kappa) Geminorum G9 III 2.3 1,890,000,000 1,890,000,000 189,000,000 7 White DwarfTejat M3 III 4.8 434,000,000 434,000,000 43,400,000 4 White DwarfAlzirr F5 IV-V 2.1 2,270,000,000 2,270,000,000 227,000,000 9 White Dwarfτ (Tau) Geminorum K2 II 3.4 865,000,000 952,000,000 8,650,000 2 White DwarfM-35, Shoe Buckle Cluster — Constellation GuideThe Shoe-Buckle Cluster looks significantly dense with small stars compared to the surrounding space. The cluster seems to be brightest near the center with a hazy yellow glow and bright white and yellow spots that dim around the edges of the group.An open star cluster is a group of many stars concentrated in a certain area. Open clusters form from a giant molecular cloud, so most of the stars contained in it are about the same age. The stars of the cluster hold gravitational pull on each other.IC 443, the Jellyﬁsh Nebula — Constellation GuideThe Jellyfish Nebula is a supernova remnant. It looks like a much larger group of stars with a similar density to the Shoe Buckle Clusterʼs density with pretty even spacing. Near the center of the Jellyfish is a large cloud with varying yellow, red and orange portions. The brightest part of the cloud is very red and yellow. There is very bright star called Propus near the outside of the cloud, but still within the overall grouping of stars. Supernova remnants are the remains of an exploded star which went supernova. The explosion of the supernova star spreads material outward in a shockwave, heating up other material nearby.To determine the length of a year, I began by marking the time that Castor rose above the horizon at the start of each week for five weeks. After taking the difference between each consecutive week, I divided these numbers by 7 for the number of days in a week. This resulted in a weekly average change of rise time for Castor of 3.93 minutes. We were able to estimate the number of days in a year at 366.4122 days by dividing the average change of rise time for Castor per day (3.93 minutes) by 1,440 minutes (the number of minutes in a given day). The tables above illustrate the results of my calculations.Average change in rise time per day: 3.93Calculated number of days in a year: 366.4122Calculated percent error: 0.32%A possible source of error in my calculations could be from not observing enough rises, there could have been greater variance in the rise times from day to day since we only observed and recorded each week over four sidereal weeks. Also, this estimation doesnʼt account for time zone changes and leap years, so that could also lead to inaccuracies. Given that the result is less than 1% of an error, using this method to estimate short periods of time would be a fine. However if used to calculate longer periods of time this would lead to some pretty big inaccuracies, because it doesnʼt account for changes in time zones, leap years, and your changing position on earth.Date Rise Time for Castor (Apollo) Hour Minute Second May 23 08 19 09 May 30 07 51 38 June 6 07 24 06 June 13 06 56 35 June 20 06 29 04       Change in Rise Time Change in Time Decimal Minutes Change in Time Per Day in minutes/day Hours Minutes Seconds 5/23–5/30 - 27 31 27.52 3.93 5/30–6/6 - 27 32 27.53 3.93 6/6–6/13 - 27 31 27.52 3.93 6/13–6/20 - 27 31 27.52 3.93  Determing the Length of a YearMythologyGemini is Latin for twins, and the constellation represents the two twin brothers, Castor and Pollux. They are the sons of Leda but have two different fathers: her husband, Tyndarus of Sparta, and Jupiter, who appeared to her in the form of a swan. Pollux was immortal and his brother, Castor, was mortal. Pollux was known for his strength and Castor for his skill with horses. They both fought in the Trojan War to bring back their sister, Helena, from capture. They typically depicted carrying spears and riding matching horses. The mythiological reason for them appearing in the stars is that Pollux was grieving the loss of his brother, Castor, and asked his father, Jupiter, to share Polluxʼs immortality with his brother, Castor. Because of the heroism displayed by both brothers, Jupiter granted them both immortality in the stars (Bell, Cathy).Works CitedBell, Cathy. “The Mythology of the Constellations.” The Mythology of the Constellations,www.comfychair.org/~cmbell/myth/myth.html. “Constellation Guide.” Constellation Guide, www.constellation-guide.com/constellation-list/gemini-constellation/.Frommert, Hartmut. IC 443, spider.seds.org/spider/Misc/i0443.html. Gemini Constellation - Facts About Gemini | Solarsystemquick.com, www.solarsystemquick.com/universe/gemini-constellation.htm.Mohon, Lee. “What Spawned the Jellyfish Nebula?” NASA, NASA, 10 Dec. 2015,www.nasa.gov/mission_pages/chandra/what-spawned-the-jellyfish-nebula.html. Castor and Pollux of Gemini — Constellation GuideFates of StarsThe following chart illustrates the fates of Castor, Tau Geminorum, and Alzirr. Each of these stars will result in a White Dwarf because they will become less than 1.4 solar masses. Tau Geminorum has the shortest remaining lifetime while Alzirr will go on for much longer. Castor overall has the shortest total lifetime Name Spectral Type Luminosity Class Mass Stages Completed Completed Lifetimes Remaining Stage Remaining Lifetimes Stellar Core Fate Mass Range Castor A1.5 IV 4.7 Main Sequence 462,000,000 Red Giant, Planetary Nebula, White Dwarf 46,200,000  White Dwarf Under 1.4 solar masses Tau Geminorum K2 II 3.4 Main Sequence, Red Giant 952,000,000 Super Giant, Planetary Nebula, White Dwarf 8,650,000 White Dwarf Under 1.4 solar masses Alzirr F5 IV-V 2.1 None 2,270,000,000 Main Sequence, Red Giant, Planetary Nebula, White Dwarf 227,000,000 White Dwarf Under 1.4 solar masses It is possible for a luminosity class III star to have a longer remaining lifetime than a class V star because the class III star is not burning through its fuel as quickly as a massive class V star. This is because there is generally more material contained within the star class V star.  A class III star will not burn through its hydrogen fuel as quick as a class V star. The graph below shows examples of this point.All ten of the stars observed end as white dwarfs.Most stars in the galaxy are less massive than our sun, so it would be a fair assumption that anything less than 8 solar masses would become a white dwarf. Therefore, I think the fate of my stars are not that far off and that stars that will not result in a white dwarf are quite rare.

https://spark.parkland.edu/cgi/viewcontent.cgi?article=1162&amp;context=nsps

Gemini

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