EDUCATIONAL
PROGRAMME "CATCH A STAR" 2004
PROJECT:
Fig.1.Team: |
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Summary
In this project
we have shown the most important and most interesting information about the
discovery and movement of a comet that was very bright in 2004 – the comet
K4 LINEAR. We have been very interested in comet observations for several years.
That is why we are presenting our observations of the comet, that we made during
the Astronomical Summer School in August 2004. The most intriguing and enjoyable
part of our project is the exercise “Make a comet and eat it”. This
amusing exercise about the nature and the movement of the comet was performed
with 12 year old students. The main character of the exercise was our comet
and we used information that we have gathered for the project in order to show
what comets are and how they move in an interesting and unforgettable way. Using
the two comet models – a comet from ice cream and a comet from paper we
demonstrated to the young students the truth in the old proverb “I heard
but forgot, I saw and memorized, I made and that is when I understood”.
Contents:
1.Introduction
2.Discovery
3. Historical Highlights
4. Orbital elements
5. We observe the comet
6. Comparison
7. Exercise: “Make a comet, eat it and think”
8. Conclusion
9. Bibliography
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Comets are the most impressive objects in the Solar system. They, together with asteroids and meteors, belong to the group of small bodies in the Solar system. Bright comets on the night sky are among the most beautiful and breath-taking sights observed in nature! In this project we present to you the bright comet K4 LINEAR that we observed during the International Astronomical Summer School in the National Astronomical Observatory in Rozhen in August 2004. |
The LINEAR project announced the discovery of an asteroidal
object on images obtained on 2003 May 28.38. The magnitude was given as
17.6. Follow-up observations were obtained by J. McGaha (Tucson, Arizona,
USA) and J. Young (Table Mountain Observatory, California, USA). McGaha
obtained CCD images on May 29.4 which revealed a nuclear condensation
3 arc seconds across and a coma 6 arc seconds across. He noted that the
coma was offset toward the northeast. Young imaged the comet on May 29.5
and May 30.4, and noted a round coma 5-7 arc seconds across, with a total
magnitude of 17.5 |
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3. Historical Highlights - history and types of observations
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• The first orbit was published
in IAU Circular 8139 (2003 May 30), which also contained the initial announcement
of the comet. It was a parabolic orbit based on 62 positions obtained
during the period spanning May 28-30 that gave the perihelion date as
2003 September 11.935 and the perihelion distance as 8.5 AU. The orbit
was considered "very preliminary". An improved orbit was published
in MPEC 2003-L29 (2003 June 7). Based on 146 positions spanning the period
of May 28 to June 6, it gave the perihelion date as 2004 October 13.50
and the perihelion distance as 1.02 AU.
• Following the discovery, the comet was well followed during the remainder of 2003. D. Tirelli (Sossano, Italy) obtained an excellent series of observations using a 25-cm reflector and a CCD camera from July through October, which revealed a brightening from magnitude 17.0 on July 3 to 15.0 on September 16. He reported slightly fainter magnitudes of 15.7 to 15.8 during the latter half of October. Before the end of 2003, R. Ligustri (Talmassons, Italy) observed with a 35-cm reflector and a CCD camera and gave the magnitude as 14.8 on December 12. |
• Because of the comet's faintness, it was
lost in the sun's glare for a short time and passed 36° from the sun
on 2004 January 22. One of the earliest observations in came from J. J.
Gonzalez (Leon, Spain) who gave the visual magnitude as 12.7 on February
17.24, while observing with his 20-cm reflector. P. Guzik (Krosno, Poland)
saw the comet with his 20-cm reflector on February 21 and gave the visual
magnitude as about 12.5. The coma diameter was given as 0.5 arc minute
by Gonzalez and 0.6 arc minute by Guzik. Following a period of moonlight,
additional observations during the second half of March revealed a magnitude
between 12 and 12.5, while the coma diameter was between 0.5 and 1.5 arc
minutes. |
![]() Fig.6 Comet C/2003 K4 07/08/2004 01:28:58, exp.120s, Filter: I Image made by: Veselka Radeva, Nadezhda Radeva and Hristo Stoev |
• The comet continued to slowly brighten during April and May. Observers generally reported a magnitude around 11.5 in the beginning of April, while it had increased to about 11 as the month ended. The coma diameter was generally around 1 arc minute during the first half of April, and was around 1.2 arc minutes as the month came to a close. M. Lehky (Hradec Kralove, Czech Republic) reporting the first observations using binoculars, which had a size of 25x100. In addition, on April 27, Walter Kutschera (Germany) reported a tail about 1 arc minute long. On May 1, observers generally estimated the magnitude as 11, while the coma was perhaps 1.2 arc minutes across. During the last days of May most observers estimated the magnitude as between 9.7 and 10.0, while the coma diameter was around 2.5 arc minutes. • Up to this point in the comet's brightness evolution, the visual observations could be represented by a fairly uneventful curve that indicated a potential maximum brightness of 7 during October of 2004, but this all changed a few days into June. By June 4, the comet had brightened to a magnitude of approximately 9.5 andwas displaying a coma about |
3.5 arc minutes across. For the most part these figures seem to have been carried over into the early hours of June 5. Late on June 5, several observers were indicating a magnitude of 8.5 or brighter, while the coma was at least 4 arc minutes across. The comet seemed to have changed only slightly in brightness by the 6th, while some observers were reporting a coma 8 arc minutes across. Many observers were now watching the comet with 7x50 binoculars and saw the comet attain a magnitude of 8 by mid-June and around 7.3-7.5 by the end of the month. Also, by the end of June, most observers were reporting a coma at least 10 arc minutes across, while the tail extended about 12 arc minutes toward PA 140°. |
![]() Fig7. Comet C/2003 K4 08/12/2004 exp.120s Filter: V Image made by: Veselka Radeva, Nadezhda Radeva and Hristo Stoev |
• The comet continued to steadily
brighten as July began. Starting out at magnitude 7.3-7.5, it was actually
seen with the naked eye by Piotr Guzik (Krosno, Poland) on July 12 at
magnitude 6.8. Guzik had also provided a fine series of observations made
with his 10x50 binoculars since July began, which consistently revealed
a coma diameter of 15 arc minutes and a tail of about 0.5°. On July
4, J. Bortle (New York) also noted a very faint outer coma 15 arc minutes
across and a bright, well condensed inner coma about 8 arc minutes across.
The comet seemed to have displayed a very slow brightening as July progressed
and, by the end of the month, it seemed to have finally reached magnitude
6.5. The coma was then generally estimated as 5 arc minutes across by
observers using telescopes and 15 arc minutes across by observers using
binoculars. These numbers changed little through mid August. |
C/2003
K4 (LINEAR) Epoch 2005 Jan. 30.0 TT = JDT 2453400.5 T 2004 Oct. 13.7148 TT q 1.023637 e 1.000324 Node 18.6754 Incl. 134.2527 |
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![]() Fig.9. Comet C/2003 K4 07/08/2004 23:45:01 Exp.120s Filter: R Image made by Veselka Radeva, Nadezhda Radeva and Hristo Stoev |
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![]() Fig.11 Comet C/2003 K4 08/12/2004 20:17:05 exp. 120s Filter: V Image made by Veselka Radeva, Nadezhda Radeva and Hristo Stoev |
![]() Fig.12 Comet C/2003 K4 08/12/2004 20:06:58 Exp.180s Filter: V Image made by Veselka Radeva, Nadezhda Radeva and Hristo Stoev |
Comet |
Period |
Type of orbit |
Types of tails |
Closest passage to the
Sun |
Image |
K4LINEAR |
- |
Parabola e=1.000324 |
Ion and dust |
153000000km 2004 Oct 14th |
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Comet Hale-Bopp |
4 200 years |
Elliptic, close to parabola e = 0.995068 |
Ion and dust |
137121300 km – 01.04.2001 |
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153P/Ikeya-Zhang |
367.17 years |
Elliptic, close to parabola e= 0.990062 |
Ion and dust |
76 million kilometers-18.03.2002 |
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C/2004 Q2 (Machholz) |
No data found |
Elliptic, close to e= parabola 0.999473 |
Ion and dust |
187500000km 2005 Jan. 24 |
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Overview: Using ice cream students
explore the anatomy of a comet. Students will learn the basic components
of a comet. They will demonstrate how the comet’s head and tail from
by building two comet models. Students will learn how the comet turns around
the Sun. Objective: To construct an edible model of a comet; to determine the anatomy of a comet; to discuss the comet orbit |
![]() Fig.14 The comet's nucleus photo:Nadezhda Radeva |
Preparation: 1. Collect the necessary ingredients as described in the materials list 2. Prepare the materials necessary for the creation of the comet from either ice cream, biscuits, walnuts and sugar, or from paper, tape and thin bands. 3. Take a sheet of cardboard and make the orbit of the comet K4 LINEAR, make small comets and put them on different places on the comet orbit. Thus you can show the development of the comet head and the comet tail. 4. Process the comet images, for example we processed the images received with 50/70 cm Schmidt telescope, so that you can understand the nature of the comet and the changes that happen with comet on its way toward the Sun. 5. Prepare the Comet Fact sheets |
Materials: 2 kg chocolate ice cream - 2 packets of biscuits – the biscuits should be in small pieces 0.5 kg nuts – the walnuts should be ground 12 plastic cups 24 plastic spoons 2 sheets of paper Yellow and blue bands Tape Glue Cloth or paper towels Hair-dryer Images of the comets |
![]() Fig.15 The necessary materials photo:Nadezhda Radeva |
Procedure:
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![]() Fig.19 Demonstration of a comet's tail-Step 8 photo:Nadezhda Radeva |
7. Make a model of a comet using a sheet
of paper and put a long yellow band (the comet tail) 8. Turn on the hairdryer in front of the comet so that the jet of air raises the bands. Explain that the jet of air is like the solar wind that leaves the Sun and fills out the interplanetary space. This explains why comet tails are always in a direction opposite the Sun. |
9. Discuss the orbit of K4 LINEAR – it is always a parabola.
Examine the position of each comet made with paper and discuss the fact
that the size of the coma and the length of the tail increase and the fact
that the direction of the tail is always opposite the Sun, Discuss the different
speed of the comet on its orbit and pat attention on the fact that when
the comet is in perihelion (the point on the comet’s orbit that is
closest to the Sun) it travels fastest (second law of Coupler). Using the
orbit elements calculate the distance between the comet and the Sun when
the comet is in perihelion. 10. Examine and compare the received images of the comet K4LINEAR and images of other comets with large bright comet tails. Discuss the similarities and the differences in the comets’ orbital parameters and the changes in the comet tails. Use the table in the project for the comet K4LINEAR and other famous comets. 11. Ask the Reflection Questions to reinforce the parts of a comet. |
![]() Fig.20.Discuss the orbit of a comet-Step 9 photo:Nadezhda Radeva |
Reflection Questions 8.
Conclusion: 9.
Bibliography: For contacts: |