A Thesis entitled A time series study of Rigel, a B8Ia supergiant
by Sara Rother
As partial fulfillment of the requirements for the Master of Science in Physics
Advisor: Dr. Nancy D. Morrison
Committee: Dr. Steven Federman
Committee: Dr. Rupali Chandar
Dr. Michael Bisesi, Senior Associate Dean College of Graduate Studies
The University of Toledo August 2009
An Abstract of
A time series study of Rigel, a B8Ia supergiant
Sara Rother
Submitted in partial fulfillment of the requirements for the Master of Science in Physics
The University of Toledo August 2009
Rigel is a B8Ia spectral type, massive, supergiant star that is experiencing mass loss in the stellar wind. The study was done with data on Rigel that was taken over the course of 10 seasons, with 192 total observations. All observations were taken with the 1.06 meter telescope at the University of Toledo’s Ritter Astrophysical Research
Center. I looked for a periodic variation in the Hα line by looking at the equivalent widths and radial velocities, as well as classifying the profiles into seven categories and determining the frequency of occurrence of each. I also measured the radial velocities of a singly ionized carbon line. A high velocity absorption event, such as the 2 seen by Kaufer et. al. in 1993 and 1994, was also seen in 2006 in this study. No single, dominant periodic component was found in the radial velocity measurements of either line.
ii Contents
Abstract ii
Contents iii
List of Figures v
List of Tables vii
1 Introduction 1
1.1 Previous Work ...... 5
2 Observations 11
3 Reduction and Analysis 16
4 Results 21
5 Discussion and Conclusions 31
5.1 Future Work ...... 33
iii A Journal of Observations 34
B Radial Velocities of Carbon II lines 43
C Radial Velocities of Hα lines in absorption 52
D Radial Velocities of Hα lines in Emission 61
References 70
iv List of Figures
1-1 P Cygni profile ...... 8
1-2 Mg II lines from Selvelli et. al...... 8
1-3 Mg II lines from Kaufer et al...... 9
1-4 High velocity absorption event seen by Israelian et al. (1997) . . . . . 10
3-1 Water Line Removal ...... 20
4-1 High velocity absorption event seen on 4 November 2006 ...... 22
4-2 High velocity absorption event seen on 10 November 2006 ...... 25
4-3 Hα in P Cygni profile ...... 25
4-4 Hα in double Emission ...... 26
4-5 Hα in Absorption ...... 26
4-6 Hα in Inverse P Cygni profile ...... 27
4-7 Hα in Double Absorption ...... 27
4-8 Hα in Emission ...... 28
4-9 Hα in triple absorption ...... 28
v 4-10 How often Rigel is in each of the profiles ...... 29
4-11 typical graph of theta vs period ...... 30
5-1 Theoretical Profile ...... 32
vi List of Tables
2.1 Wavelength range of each Echelle´ order ...... 12
4.1 How often each profile type is seen in the observations ...... 23
A.1 Journal of Observations ...... 34
A.1 Journal of Observations ...... 35
A.1 Journal of Observations ...... 36
A.1 Journal of Observations ...... 37
A.1 Journal of Observations ...... 38
A.1 Journal of Observations ...... 39
A.1 Journal of Observations ...... 40
A.1 Journal of Observations ...... 41
A.1 Journal of Observations ...... 42
B.1 Radial Velocity of Carbon II lines at 6578 A˚ and 6582 A˚ ...... 43
B.1 Radial Velocity of Carbon II lines at 6578 A˚ and 6582 A˚ ...... 44
B.1 Radial Velocity of Carbon II lines at 6578 A˚ and 6582 A˚ ...... 45
vii B.1 Radial Velocity of Carbon II lines at 6578 A˚ and 6582 A˚ ...... 46
B.1 Radial Velocity of Carbon II lines at 6578 A˚ and 6582 A˚ ...... 47
B.1 Radial Velocity of Carbon II lines at 6578 A˚ and 6582 A˚ ...... 48
B.1 Radial Velocity of Carbon II lines at 6578 A˚ and 6582 A˚ ...... 49
B.1 Radial Velocity of Carbon II lines at 6578 A˚ and 6582 A˚ ...... 50
B.1 Radial Velocity of Carbon II lines at 6578 A˚ and 6582 A˚ ...... 51
C.1 Radial Velocity of Hα lines in absorption ...... 52
C.1 Radial Velocity of Hα lines in absorption ...... 53
C.1 Radial Velocity of Hα lines in absorption ...... 54
C.1 Radial Velocity of Hα lines in absorption ...... 55
C.1 Radial Velocity of Hα lines in absorption ...... 56
C.1 Radial Velocity of Hα lines in absorption ...... 57
C.1 Radial Velocity of Hα lines in absorption ...... 58
C.1 Radial Velocity of Hα lines in absorption ...... 59
C.1 Radial Velocity of Hα lines in absorption ...... 60
D.1 Radial Velocity of Hα lines in Emission ...... 61
D.1 Radial Velocity of Hα lines in Emission ...... 62
D.1 Radial Velocity of Hα lines in Emission ...... 63
D.1 Radial Velocity of Hα lines in Emission ...... 64
D.1 Radial Velocity of Hα lines in Emission ...... 65
viii D.1 Radial Velocity of Hα lines in Emission ...... 66
D.1 Radial Velocity of Hα lines in Emission ...... 67
D.1 Radial Velocity of Hα lines in Emission ...... 68
D.1 Radial Velocity of Hα lines in Emission ...... 69
ix Chapter 1
Introduction
Rigel is a well-known, bright star in the constellation of Orion. It is the brightest star in Orion, at a visual magnitude of 0.12. It has a spectral type of B8Ia. The luminosity class shows that it is a bright supergiant. It has a scientific name of
β Orionis A. It also has the names of HR 1713, HD 34085, 19 Ori, as well as the common names of Algebar and Elgebar. Rigel is located close to the celestial equator; its coordinates are Right Ascension: 05h14m32s Declination: −08◦ 1200500 for epoch
2000.0. Its galactic coordinates are 209◦ longitude and −25◦ latitude.
Rigel is important in many ways. It is a supergiant star, which means that it is one of the most massive stars. Massive stars are important because when they end their lives they form supernovae, which can then enrich the interstellar medium by releasing heavy elements. Massive stars also have mass loss during their lifetimes, which can affect the precise nature of the supernova. The supernova is very sensitive to end mass, and will affect how many elements heavier than helium are released.
Rigel is near the end of its life, which is typically very short; for this type of star, the main sequence lifetime is around 50 million years. It is also a variable star. Its
1 2
H-alpha profile varies over a short range of time, as short as 1 day.
Some of the basic properties of Rigel have been established in the literature (Is- raelian et al. 1997 and Kaufer et al. 1996a,b). The stellar radius is around 130 R¯. The effective temperature is 13000 ± 500 K. The luminosity is 105.63±0.06 times the solar luminosity. It now has a mass of around 24 M¯, but when it was at its zero age main sequence point, its mass was about 31 M¯. It is losing mass at a rate of about 1 × 10−6±0.5 solar masses per year, although this rate is not constant, and has not always been the same. The B-V value is -0.03 and its color excess E (B-V) is 0.00.
Rigel has a parallax angle of 4.22 ± 0.81 milliarcseconds, which gives it a distance of around 237 ± 57 parsecs, or around 775 lightyears. This was estimated using the
Hipparchos data from Perryman (1997). The projected equatorial rotational velocity
(v sin i) is 40 km s−1, which has been found from the line width by Israelian et al.
(1997). Rigel has a gravity of log g [cm s−1] of 1.6, which was found by Israelian et al.
(1997). This is the gravitational acceleration. The value on the surface of the earth is 980 cm s−1, which would give a log g of around 3. The supergiant’s gravity is much lower because it has such a large radius, and is not very dense, and the atmosphere
39 3 is not compact. Using the radius of 130 R¯, the volume of the star is 3.10 × 10 m . This gives a density of 1.54×10−5 g cm−3. Severny (1970) found a magnetic field of
130 Gauss in Rigel, which was the first detection of a magnetic field in a non-main sequence star.
Rigel is not alone in its orbit; it is part of at least a triple star system. The secondary star has been resolved, as a main sequence star, with a spectral type of B9, and a visual magnitude of 7.6. They have an angular separation of 9.6 arcseconds, which gives a true separation of 2275±536 AU. The tertiary star is too close to the 3 secondary to resolve; it was seen spectroscopically. These stars are so far from Rigel that they will not affect it on the timescale of this study, since the period of the second and third stars around Rigel is about 1×105 years.
I studied a line from the hydrogen atom. The electron in an atom can be excited to get into different states, when a photon with that specific energy interacts with it. If the electron is in the ground state, and a 10.2 eV photon interacts with it, it moves from level n=1 to level n=2 (where n is the principal quantum number), and will absorb the photon, obtaining the energy. It can then reemit a photon with the same energy, and the electron will drop from level 2 to level 1. The first set, from level one, is called the Lyman series. The alpha line is from level 1 to 2, the beta from level 1 to 3, and the gamma from level 1 to level 4. The second set is called the
Balmer series. The third set is called the Paschen, the fourth is the Brackett, and the
fifth is the Pfund. We want to use the first line in the Balmer series, Balmer alpha
(Hα) to study Rigel; this line has a wavelength of 6562.817 A.˚ Hα is used because it is the most sensitive tracer for variability of the stellar wind in the visible range for
BA type supergiants, because of the oscillator strength.
Electrons must only exist in quantized states. The principal quantum number designates the energy level of the atom. When a photon with the appropriate energy strikes a hydrogen atom in the n=2 state, the photon bumps up the electron from level 2 to level 3, while the electron absorbs that photon. As the electron goes back down to level 2, it reemits that same wavelength photon. This is how a photon can get scattered. The first direction is radially out of the star, but after scattering, it can be in any direction. 4
The atom can also get ionized. It takes 13.6 eV to ionize hydrogen, and the electron will then detach from the atom. To get it from level 1 to level 2, it takes about 10.2 eV, which is almost completely ionized. In a B8 star like Rigel, the surface temperature is around 13000 K, which has energy (kT) just over 1 eV, and emits a large quantity of UV photons which can collisionally and radiatively excite the electron in hydrogen to a higher level. This is close to the energy required to get the atom from level 2 to level 3. The electron can get ionized by surrounding photons, and then re-combine with the atom. The electron can then re-combine into a higher level than what it had originally, and some electrons cascade down to the ground level, which is another main source for emission of Hα.
A supergiant star experiences mass loss, which is not constant over the lifetime of the star. This can be seen in the spectrum, with the Mg II and Hα lines. A
P Cygni profile was first observed in the star P Cygni, which shows evidence for mass loss. A P Cygni profile (Fig 1-1) is characterized by absorption that is blue shifted, and emission that is slightly red shifted with respect to the rest wavelength of H-alpha. The blue shifted portion is due to the near side of the expanding shell of material coming toward the observer. This is seen in absorption because the star is directly behind the expanding gas. The red shifted portion is from the far side of the expanding envelope moving away from the observer, and is seen against the cold background of space, so it is in emission. P Cygni has a much higher emission level than Rigel, since it is a B2 star, is hotter, and produces more UV photons.
The emission should be mainly from rest, since most of it comes from the sides of the star, where there is no Doppler shift as seen from an observer on Earth. Broad absorption can take away some of the emission close to the rest wavelength, so the leftover emission looks more red shifted than atoms in the wind that are moving away from the star, so they are absorbing a red shifted photon from the star. In turn, they 5 re-emit a red shifted photon.
The stellar wind is a flow of ionized particles that is ejected from the upper at- mosphere of the star, which contributes directly to mass loss. It is likely driven by radiation pressure in the photosphere of the star, with the heavy elements, usually carbon and nitrogen. It yields very high velocities, up to 2000 km s−1.
1.1 Previous Work
Selvelli et al (1977) and Kaufer et. al. (1996a) looked at Mg II lines in the spectrum of Rigel. These lines show the best evidence of mass loss in the complete optical range.
Mg II lines are found in the UV at around 2800 A;˚ the two lines are at 2795.52 A˚ and
2802.70 A,˚ see Figs 1-2 and 1-3. The Copernicus satellite was used by Selvelli et al.
(1977), and Kaufer et al. (1996a) used the IUE satellite to obtain the ultraviolet data. Mg II lines were seen with radial velocities near -200 km s−1. The resonance lines of Mg II are the deeper ones from the ground state and smaller, shallower ones are from excited states in Fig 1-2. Ground state lines are favored when density is low, like in the stellar wind, and more atoms exist in the ground state, leading to a higher population available to be excited. Optical depth reaches 2/3, the critical value, in the wind in stronger, deeper lines, while the shallower lines reach that critical depth in the photosphere. The resonance lines in Fig 1-3 have the longest wavelength, which are the rightmost in the figure, and are formed in the photosphere. Of the stars in the figure, HD92207 has the strongest Mg II lines and has a fully P Cygni profile in
Hα. The interstellar medium also contributes to the resonance line, since its density is also low, which can make the line appear deeper. 6
Kaufer et al. (1996a,1996b,1997) wrote a 3 paper sequence on BA supergiants. The group did a long term spectroscopic monitoring program over 3 observing seasons, with a total of 194 observations, in order to look at variability of these supergiants.
They wanted to get a large spectral range, with a high signal-to-noise. They see high velocity absorption events, which they note as extraordinarily deep and very blue- shifted absorption events. The cut-off value for these high velocity absorption events in Rigel is -200 km s−1. This level is important because it is a substantial fraction of the terminal wind velocity. The absorption also has to reach down to a level of
10 to 50 percent below the continuum. These events do not propagate out in the wind, but do drift down to more negative velocities. They saw 2 events in Rigel, one is 1993 on Modified Julian Date of 49295, and the blue-edge velocity reached -238 km s−1, and the absorption reached down to 46 percent of the continuum. The other event was in 1994, on MJD of 49403. The blue-shifted velocity reached -278 km s−1, and the absorption reached down to a very low level of 20 percent of the continuum.
These events had a timescale that was less than the dynamical timescale of the wind.
The dynamical timescale of the wind is the time that it takes a test particle to travel from the photosphere of the star to the edge of the wind. If the timescale was more than the dynamical timescale of the wind, then the change could be coming from the wind as a whole; however, if the timescale is less than the dynamical timescale, then the change is occurring somewhere in the wind. Kaufer et al. 1996a wanted to know what was causing this change.
Israelian et. al. (1997) derived many of the fundamental properties of Rigel from their study. They used non-LTE atmosphere models with the TLUSTY program.
They also saw the High Velocity Abosprion event in 1993, which they believe is at a maximum, Fig 1-4, as well as the variability of the Hα line, which was explained by large spots on the surface of the star, which can lead to extended loops. 7
Takeda et al. (1995) talked about getting the rotational velocity of Rigel, from the
He I line at 6678.15 A,˚ and wanted to separate out the rotational velocity (v sin i) from the macroscopic turbulent velocity field ζ. This is difficult because rotation and macroturbulence both can broaden the line in the same way, and the lower surface gravity increases ζ, while the large radius decreases the v sin i. Takeda et al (1995) found that the v sin i is 40 ± 6km s−1, and the ζ to be 43 ± 8km s−1. This is in agreement with earlier work by Gray (1975).
Some of the questions I am trying to answer are: Is there an aspect of the Hα or the entire line profile that is periodic? Is there a periodic component to the Hα profile?
How does it vary over time? How and why does the stellar wind vary over time? How and why does the Hα profile change over time? Will there be any more of the high velocity absorption events, such as those seen by Kaufer, and if so, will they occur at a specific interval? 8
Figure 1-1: P Cygni profile
Figure 1-2: Mg II lines in the spectrum of Rigel from Selvelli et al. (1997) The lines at 2795 and 2803 are formed in the photosphere (resonance lines), while the other lines are formed in the wind of the star. 9
Figure 1-3: Mg II lines in the spectra of 5 stars from Kaufer et al. (1996a). 10
Figure 1-4: Absorption event (02.11.93) seen by Israelian et al. (1997) in 1993, as well as variability of the Hα line Chapter 2
Observations
All of the observations were taken at Ritter Observatory, which is located on the main campus of The University of Toledo in Toledo, Ohio; Ritter Observatory is part of the Ritter Astrophysical Research Center. The telescope has a primary mirror diameter of 41 inches, or 106 centimeters. It is a Ritchey-Chretien reflecting telescope, with an f ratio of f/8. The focal length is 8.48 meters. It has all reflecting optics.
A fifteen-meter long fiber optic cable is used to transport the light from the telescope to the bench-mounted camera on another floor of the building, with the cable’s core diameter being 200 µm. The plate scale is 24.33 arcseconds/mm, which means the
fiber covers an area of 4.866 arcseconds of the sky. The light loss in the fiber is negligible; most light loss comes from poor focus and the effect of atmospheric seeing.
The ´echelle is a diffraction grating that is used for high diffraction orders. The light
first passes through a slit, and is directed onto the collimator mirror. That light is then reflected by the ´echelle grating, which is reflected at a high blaze angle of 63.5 degrees. The light is then reflected by a second, crossed grating to separate the orders from overlapping with each other. The light is focused onto a charge coupled device
11 12
(CCD) by a camera mirror and then strikes the CCD. The ´echelle grating has 79 grooves per millimeter. It has an incidence angle of 68o and a blaze angle of 63o. The collimator, which is an optical element that takes a diverging beam into a parallel one, has a focal length of 54 centimeters and a diameter of 7 centimeters. The camera has a focal length of 75 centimeters. David Latham of Harvard College Observatory made the original design of the ´echelle spectrograph.
The ´echelle spectrograph has many orders, of which 9 can be displayed on the CCD at once, because the CCD is smaller than the entire spectrum. The total range that was used was 5285 to 6594 A˚ for all nine orders. Each order is about 70 A,˚ with a gap in between of about 100 A.˚ See Table 2-1 (Morrison 2008) for the full wavelength coverage. The range is 6527 to 6594 A˚ for the order of interest, since the Hα rest wavelength is in this range.
Table 2.1: Wavelength range of each Echelle´ order
Echelle´ Order Wavelength Range ( A)˚ 34 6527 - 6594 35 6340 - 6406 36 6165 - 6230 37 5998 - 6060 38 5840 - 5901 39 5691 - 5750 40 5550 - 5606 41 5413 - 5470 42 5285 - 5339
The camera system, which is the CCD and dewar, is by Wright Instruments Ltd.
The camera and spectrograph system has a CCD used to collect the light. It is a front-illuminated CCD manufactured by EEV, with 1200 × 800 pixels of dimensions
22.5 × 22.5µm. The camera is cooled by a liquid nitrogen system to an operating 13 temperature of 140 K. The CCD is coated with coranine, which is a special dye that is used to make CCDs more sensitive to blue light. It works by absorbing blue light and re-emitting it at a longer wavelength, since CCDs are much more sensitive to red light. The camera is no longer in use. It was in use throughout the entire run of this time series analysis, as it was taken off line in April 2007.
The spectrograph and camera together have a resolving power of 26000. This is a function of the width of the image of the entrance slit on the CCD. In the case of
Ritter, this is 4.3 pixels. This is actually oversampled, as the optimum is 2 pixels.
This is because the signal can be modeled by a superposition of sin and cosine waves, and the most efficient way to sample that is by using 2 samples per period. The
Nyquist frequency is one half the highest frequency present in the data, which is given by the pixel size.
A typical night of observing starts with taking 5 bias frames. A bias is used to get the base noise level, since the shutter is kept closed for the exposure. It is essentially an exposure for zero seconds. Next, a flat spectrum is taken. This is an exposure of a white lamp that is a continuous blackbody spectrum. This is used to determine where each order is located on the CCD. It is also used to determine pixel by pixel differences. Then a comparison lamp exposure is taken. For all the observations of
Rigel, we used a Thorium-Argon lamp, which has lines distributed all over the visible spectrum. The comparison lamp is used to determine the wavelength calibration. A comparison exposure is taken before and after every stellar observation. A velocity standard star is observed every night. Repeated observations of these stars yield standard deviations in their velocity measurements from 200 m s−1 to 1 km s−1. Some of these standard stars have a larger standard deviation because they are variable.
These standard stars have been used for many years, and until recently, when more 14 precise observations were taken, these stars were not known to be variable. These standard stars have very sharp lines and short exposure times, and must be bright.
Rigel also requires a short exposure time, but lines are not as sharp, due to broadening of the lines, so the radial velocity standard deviations are a lower limit for the radial velocity error of Rigel. Most of the observations are 300 seconds in duration, but some are longer due to bad seeing, or some light cloud cover.
As with all research, there is always a human factor involved, which can lead to some variations in the data quality. Some people will observe through thicker clouds.
Focusing is not automatic, and people have different eyes, and level of experience with the equipment. If the star is not directly on the fiber, then not all of the light goes down the fiber into the camera system. The telescope system does not track perfectly, so the observer has to constantly watch the star’s image and make sure it stays directly centered over the fiber. There were 24 different observers over the course of the 10 season observing program; the list is located in Table A.1. In Table
A.1, the counts are measured in ADUs or analog to digital converter units, which is just a measure that the spectrograph gives based on photon count, which is taken at the highest point in average of all rows in the spectrum.
192 observations were taken from February 9th 1997 to March 8th 2007. I wanted to only use data where a signal to noise ratio (SNR) of around 100 had been achieved.
This means that the signal is over 100 times greater than the any noise. The most common cause of noise is photon noise, because in order to get a SNR of 100, you need to count 10000 photons. This high SNR leads to a higher quality image. More observations had been taken during the time frame, but had to removed because they did not meet the signal to noise minimum level. 15
The observations were taken when the star was as close to the zenith as possible.
This makes the observing season relatively short, since this is a southern star, and is only visible for 5 months out of the year, from late October to April, which leads to unequal sampling. There will be large gaps with no data, as well as the fact that the star is not observed every night. The unequal sampling must be taken into account while performing the analysis of the period. Chapter 3
Reduction and Analysis
The data were obtained from the Ritter archive. I then went through a series of steps, which included extracting the aperture with Hα, calculating the airmass, removing cosmic rays, removing water lines, normalizing the continuum to unity, and changing to heliocentric Julian date. I also used an observation of the star alpha Leo, which is a telluric standard star, to make a water template.
I used IRAF (Image Reduction and Analysis Facility) to do all of my analysis of the data. IRAF was developed by the National Optical Astronomy Observatory (NOAO).
I examined the order that contained the Hα line, as well as both of the carbon lines.
I calculated the airmass by inputting into IRAF the coordinates of Ritter Obser- vatory. Airmass is defined as the path length of atmosphere that an observation is made through. The zenith is defined as having an airmass of 1. The airmass increases by approximately sec z, z being the angle from the zenith, with the approximation holding for small z. The sidereal time was then used, along with the universal time and hour angle to calculate the airmass. Typical values are between 1.1 and 2, with
2 being the highest value that I wanted to use.
16 17
Cosmic ray hits are identified as being at least one pixel that is significantly higher than the neighboring pixels. Since typical features are at least 4 pixels wide at the full width at half maximum, cosmic rays stand out as being much thinner. They are caused by a particle hitting the CCD, and causing a large flux of electrons at that one pixel.
The water lines are removed using the IRAF task telluric. A template is used, with the water lines known, in order to remove the lines from each spectrum. I made the template from a standard star. A telluric standard was used, which has very broad features. I used data from Hinkle et. al. (2000) to get the precise wavelengths of 10 water lines. Telluric calibrations are shifted and scaled to best divide out the water line features from the data. The program gives a best estimate, which can then be manually corrected. Fig 3-1 shows a typical spectrum with the water lines removed compared to having the water lines included.
All of the spectra had different photon count numbers, depending on the exposure time, the cloud cover at the time, the hour angle, and the seeing conditions. In order to compare each spectrum with all the others, the continuum must be normalized to one. This was done by using the IRAF task continuum. I used the outer 20 A˚ of the continuum, 10 A˚ at each end, as a baseline. A straight line fit can be assumed because the CCD only takes a small portion of the entire ´echelle, and the other orders all have a linear shape, and it can be assumed to be smooth far away from Hα. The program then divides the entire spectrum by this line. The relative emission and absorption can then be compared.
The Heliocentric Julian Day (HJD) is the same as the Julian day, but adjusted to the frame of reference of the center of mass of the solar system, which is inside the 18
Sun, and can differ from the Julian day by as much as 8.3 minutes, the time it takes the Sun’s light to reach Earth. It can be a shorter time depending on where the Earth is in its orbit.
The radial velocities were measured, of the absorption and emission components of the Hα line as well as the C II line. The radial velocities were measured using the
IRAF task splot. I measured each line with a Guassian, Lorentian, or Voigt profile, and picked the one that best fit the line profile. The radial velocity was choosen at the peak of each profile. The radial velocities were also heliocentrically corrected for the Earth’s motion around the Sun.
I then went through all of the observations, and classified each H-alpha profile into one of the 7 categories: absorption, double absorption, triple absorption, emission, P-
Cygni, Inverse P-Cygni, and double emission. Absorption was defined by the profile being entirely below the continuum. Emission was defined by the profile being totally above the continuum. Double absorption or emission was defined by two distinct peaks. P-Cygni was defined by blue-shifted absorption and red-shifted emission.
Inverse P-Cygni is defined by blue shifted emission and red-shifted absorption. The different categories are seen due to the fact that Rigel is a variable star and there could be possible clumping in the stellar wind.
The IRAF task PDM (phase dispersion minimization) was used with the positive and negative absorption and emission values of Hα , as well as the two C II lines. This task is used to find periods in data. The task PDM starts by choosing a period, and then arranging the data by phase according to that period, treating all observations as though they were made in the same phase. It then divides the phase into bins, and then takes the standard deviation of each bin. This is called phase dispersion 19 minimum, and is done by a least squares fitting technique with respect to the mean curve of the mean of each bin, to determine periodicities and calculate the amplitudes and epochs. It then calculates a Θ statistic, eqn 3.1, which is the sample variance
(variance of each bin), eqn 3.3 divided by the variance of the entire sample eqn 3.2, with M samples taken from N points, as shown in Stellingwerf (1978), and then finds the period where Θ is at a minimum.
Θ = s2/σ2 (3.1)
Σ(x − x¯)2 σ2 = i (3.2) N − 1
Σ(n − 1)s 2 s2 = j j (3.3) Σnj − M 20
Figure 3-1: A typical P Cygni spectrum shown with (solid line) and without (dashed line) the telluric lines Chapter 4
Results
A very important result of this study was determining the radial velocities. I first started with measuring radial velocity of the C II lines, which are given in B.1. The
6578 A˚ line of C II has an average radial velocity of 21.5 km s−1, with a standard deviation of 4.68 km s−1. The 6582 A˚ line of C II has an average radial velocity of
21.9 km s−1, with a standard deviation of 6.88 km s−1. I wanted to obtain a measure for both lines of C II in order to make sure they were similar, and they were within the standard deviations The total average Hα absorption radial velocity is 8.0 km s−1with a standard deviation of 29.5 km s−1, and the total average Hα emission radial velocity is 14.7 km s−1with a standard deviation of 17.7 km s−1; this is different from the carbon lines because the Hα line can be red or blue shifted, and can have as many as 3 components. The Ritter spectrograph has an error of around ±1 km s−1. The standard deviations are more than 3 times the expected error, which is an indication that these lines are variable. This would make sense, since Rigel is a pulsating star, and would be expected to have lines with changing radial velocities.
21 22
In my study, I saw a High Velocity Absorption event similar to the one seen by
Kaufer et. al. (1996a) and Israelian et. al. (1997) (Fig 1-4). It occurred on both
4 November 2006 Fig (4-1) and 10 November 2006 (Fig 4-2). This was presumably the same event, but at different stages; there was no data taken in the interviening nights, and the radial velocity of the Hα line can be clearly seen to be more negative than -200 km s−1, with a value of -200.2 km s−1.
Figure 4-1: High velocity absorption event seen on 4 November 2006
The Hα profile is most often found in the P-Cygni profile (Fig 4-3), followed by double emission (Fig 4-4), absorption (Fig 4-5), inverse P-Cygni (Fig 4-6), double absorption (Fig 4-7), emission (Fig 4-8), and lastly triple absorption (Fig 4-9). The results are summarized in Table 4.1, and Fig 4-10.
In data tables B through D in the appendices, the radial velocities are given. In
Table B.1 the radial velocities of both of the carbon lines are given. In Table C.1, the radial velocities of the Hα line in absorption are given, and the average was -68.02 23
Table 4.1: How often each profile type is seen in the observations
Profile Type Number Percentage P Cygni 46 23.9 Double Emission 42 21.9 Absorption 41 21.4 Inverse P Cygni 32 16.7 Double Absorption 26 13.5 Emission 3 1.5 Triple Absorption 2 1
km s−1 for the negative component, +8.04 km s−1 for the central component, and
+64.71 km s−1 for the positive component. In Table D.1, the radial velocity of Hα in emission is given, and the average was -59.44 km s−1 for the negative component, and +88.79 km s−1 for the positive component.
In the IRAF task PDM, I looked for a period of 10 to 100 days. I graphed the theta (Θ) statistic versus the period in Fig 4-11 . The Θ statistic is defined as the sample variance of x divided by the true variance of x. If the period is not a real period, than these variances will be the same, and Θ will be 1; however if it is a real period of the data, then Θ will be a minimum compared to local data. None of the periods were statistically significant in this case, which could be due to the fact that the data were sampled so unequally, and that there could be more than one period present.
Usually an inverse P Cygni profile is evidence for infalling matter. However, since this is a supergiant star, that explanation is difficult to reconcile, since supergiants have stellar winds, and push the mass outward. There must be some other expla- nation for the Inverse P Cygni profile. The wind may be partially transparent, due to clumping, and therefore one can catch a glimpse of the photospheric absorption 24 through this less dense area; if a small part is glowing less brightly, such as small structures near the star, or less dense regions, due to possible clumping, it can cause the Inverse P Cygni profile. These small bumps do not always tell you about the global structure of the wind. By the same argument, a P Cygni profile does not always mean that there is outflow. 25
Figure 4-2: High velocity absorption event seen on 10 November 2006. This is presumably the same event as seen on 4 November 2006.
Figure 4-3: Hα in P Cygni profile. This and subsequent figures have been binned, with 2 pixels binned into 1. This was done to help reduce the apparent noise. 26
Figure 4-4: Hα in double Emission
Figure 4-5: Hα in Absorption 27
Figure 4-6: Hα in Inverse P Cygni profile
Figure 4-7: Hα in Double Absorption 28
Figure 4-8: Hα in Emission
Figure 4-9: Hα in triple absorption 29
Figure 4-10: How often Rigel is in each of the profiles 30
Figure 4-11: typical graph of theta vs period Chapter 5
Discussion and Conclusions
Although there was no periodicity found in this study, there could still be a periodic component in the Hα profile of Rigel, because the data was so unequally sampled, it might have been missed. A longer, more complete study would help to pin down an exact period if there is one. There may also be a multi-periodic component. This could be caused from clumping in the stellar wind. Multiple clumps could possibly be present in the wind, and as they each move in and out of view, it would change the look of the Hα profile.
A theoretical line profile can be used to represent the photosphere. The theoretical line profile is from Hubeny et al. 1989. It used an effective temperature of 15000 K and log g of 1.65. The absorption profile during the high velocity absorption event is deeper than can be explained by the theoretical profile for the model photosphere
(Fig 5-1), so there must be something else to explain it. One possibility is infalling matter with a magnetic field. According to theoretical models, infall in the presence of a stellar wind can be explained if a magnetic field is controlling the flow of material.
31 32
This study has more extensive duration coverage compared to Kaufer et al. (1996a,
1996b, 1997), with 10 observing seasons, from 1997 to 2007, and a total number of
192 observations, compared with only 3 seasons of observing time, from 1992 to 1994, with 194 total spectra. Kaufer et al. (1996a, 1996b, 1997) had more time during each season, and less gaps between consecutive observations, while I have a longer duration but with more time between each observation. The two studies together give a wider view of Rigel.
An advantage of this study is that all of the observations were taken with the same equipment, including the same camera. All of the observers had the same training.
This makes comparing the spectra over different seasons feasible. Each spectrum is normalized the same way.
Figure 5-1: Rigel’s spectrum (solid bold line) of a High Velocity Absorp- tion Event with a theoretical profile for the photosphere (dashed line) that has been shifted up to match the continuum level from Morrison et al. (2008). 33
In conclusion, it has been learned that the Hα profile in Rigel is highly variable, and that we did not find a single periodic component. It has also been shown that a similar
High Velocity Absorption event like the one that occurred in 1994 has happened again in 2006.
5.1 Future Work
For future work, a study of a longer period of time would be helpful in order to determine if there was a periodic relation at all, and analysis of the data for different period time scales, and to see if a multiple period could exist. A Fourier transform analysis of the period might prove more useful in obtaining results, along with a
Lomb-Scargle periodogram and other analysis techniques that can deal with unequal sampling. Better and more precise values of the magnetic field could help determine what effect this has. More precise values for the stellar wind could determine if there is clumping involved, and help to explain why the profile varies over time.
Another study later in time would be useful to determine how often the High Velocity
Absorption event occurs, and whether it is similar every time. Collaboration with other observatories could help get closer to equal sampling, and observatories in the southern hemisphere could help fill in the gaps when Rigel is not visible from Toledo,
Ohio. Appendix A
Journal of Observations
Table A.1: Journal of Observations
Date (YYMMDD) Heliocentric Julian date ADU Observers
970209 2450488.623 3321 CLM
970225 2450504.557 701 DCK,CLM,NDM
970226 2450505.562 342 DCK
970311 2450518.575 586 NDM,CLM
970312 2450519.588 362 DCK
970320 2450527.533 99 NDM
970320 2450527.536 239 NDM
971127 2450779.824 3638 NDM,AM
971216 2450798.745 778 KSB,CLM
971218 2450800.776 1537 TLS,AM
980114 2450827.658 1433 NDM,DCK
980203 2450847.619 1209 NDM,CLM
980207 2450851.622 503 CLM
980208 2450852.603 776 CLM,NDM
34 35
Table A.1: Journal of Observations
Date (YYMMDD) Heliocentric Julian date ADU Observers
980215 2450859.587 733 AM
981127 2451144.808 551 NDM
981128 2451145.783 830 NDM
981202 2451149.793 692 DCK,CLM
981209 2451156.756 749 DCK,CLM
981210 2451157.723 826 NDM
981212 2451159.766 688 NDM,PAO
981215 2451162.733 952 KSB,NDM
981216 2451163.722 769 NDM,CLM
990130 2451208.573 177 NDM
990130 2451208.579 125 NDM
990130 2451208.585 140 NDM
990210 2451219.643 72 KSB,DCK
990211 2451220.637 252 NDM
990214 2451223.608 487 DCK,NDM
990215 2451224.565 472 HR,NDM
990216 2451225.627 349 WJF,NDM
990222 2451231.56 391 HR,NDM
990223 2451232.541 131 NDM
990223 2451232.55 145 NDM
990302 2451239.536 569 NDM
990305 2451242.516 483 NDM
990313 2451250.539 342 NDM
990313 2451250.547 327 NDM 36
Table A.1: Journal of Observations
Date (YYMMDD) Heliocentric Julian date ADU Observers
990315 2451252.527 536 NDM
990317 2451254.521 276 KSB
990320 2451257.523 305 NDM
990324 2451261.526 226 NDM
991027 2451478.851 507 KSB,WJF
991028 2451479.825 747 AM
991029 2451480.869 745 KSB,WJF
991108 2451490.804 1156 AM,DCK
991109 2451491.793 336 AM
991115 2451497.81 562 AM
991116 2451498.829 734 AM
991118 2451500.796 745 KSB,AM
991119 2451501.812 424 KSB,WJF
991128 2451510.77 1128 AM
991130 2451512.768 679 AM
991211 2451523.754 952 AM
20000125 2451568.729 426 AM,DCK
20001012 2451829.87 557 WJF,DCK
20001030 2451847.8 699 DCK
20001105 2451853.879 1319 NDM,DCK
20001223 2451901.735 271 NDM,AM
20010109 2451918.711 188 NDM,DCK
20010109 2451918.706 217 NDM,DCK
20010110 2451919.75 312 NDM,AM,DCK 37
Table A.1: Journal of Observations
Date (YYMMDD) Heliocentric Julian date ADU Observers
20010111 2451920.787 264 AM,DCK
20010121 2451930.675 242 NDM
20010126 2451935.659 257 AM
20010128 2451937.604 489 NDM,DCK
20010211 2451951.568 326 NDM,DCK
20010213 2451953.666 282 WJF,AM
20010219 2451959.627 292 NDM,DCK
20010221 2451961.625 256 KSB,AM
20010222 2451962.606 169 WJF,DCK
20010222 2451962.618 159 WJF,DCK
20010224 2451964.518 241 NDM
20010228 2451968.594 521 KSB,NDM
20010302 2451970.607 213 AM,JPW
20010304 2451972.594 344 NDM
20010308 2451976.599 429 WJF,DCK
20010311 2451979.578 168 AM
20010312 2451980.597 468 AM
20010318 2451986.632 763 NDM,DCK
20010319 2451987.601 491 NDM,AM
20010323 2451991.575 235 AM,JPW
20010323 2451991.611 184 AM,JPW
20011106 2452219.784 612 JPW
20011112 2452225.825 617 NDM
20011122 2452235.801 595 NDM,AM 38
Table A.1: Journal of Observations
Date (YYMMDD) Heliocentric Julian date ADU Observers
20011123 2452236.828 589 NDM
20011221 2452264.748 576 NDM,JPW
20011222 2452265.701 824 NDM,JPW
20020120 2452294.656 228 AM
20020122 2452296.671 379 KSB,JPW
20020125 2452299.635 372 AM
20020127 2452301.624 503 NDM
20020128 2452302.603 436 JT
20020202 2452307.613 653 NDM
20020203 2452308.627 683 NDM,AM
20020205 2452310.609 252 KSB,JPW
20020206 2452311.577 384 NDM,AM
20020208 2452313.597 392 AM
20020209 2452314.569 508 NDM,JPW
20020210 2452315.515 365 JPW
20020214 2452319.582 329 ACG,NDM,JPW
20020215 2452320.576 220 AM
20020218 2452323.597 457 JT,NDM
20020219 2452324.63 155 KSB
20020223 2452328.529 543 NDM,JPW
20020225 2452330.54 784 AM
20020302 2452335.522 516 NDM
20020307 2452340.557 179 ACG,NDM
20020311 2452344.521 372 NDM,AM 39
Table A.1: Journal of Observations
Date (YYMMDD) Heliocentric Julian date ADU Observers
20020331 2452364.556 457 NDM,AM
20021207 2452615.765 308 JPW
20021215 2452623.658 368 JPW
20030107 2452646.735 321 NDM,AM
20030118 2452657.713 295 NDM
20030122 2452661.626 362 JPW
20030130 2452669.69 270 NDM
20030131 2452670.644 343 NDM,JPW
20030206 2452676.624 392 NDM
20030214 2452684.601 730 JPW,AM
20030220 2452690.584 354 NDM,AM
20030221 2452691.651 541 JPW,NDM,AM
20030227 2452697.573 452 NDM,AM
20030303 2452701.57 381 NDM
20030307 2452705.567 203 JPW,AM
20030311 2452709.529 281 JPW,AM
20030314 2452712.536 940 JPW,AM
20030315 2452713.581 564 NDM
20030316 2452714.579 302 NDM
20030324 2452722.557 971 NDM
20031109 2452952.847 405 DRL, AM
20031121 2452964.793 302 JT, AM
20031121 2452964.805 707 JT, AM
20040209 2453044.537 335 JT,NDR 40
Table A.1: Journal of Observations
Date (YYMMDD) Heliocentric Julian date ADU Observers
20040212 2453047.611 321 NDM, ENH
20040218 2453054.612 216 KSB
20040226 2453062.602 482 NDM, ENH
20040228 2453064.524 408 NDM
20040229 2453064.569 461 NDR
20040310 2453074.564 110 DRL
20040310 2453074.608 270 DRL
20040311 2453075.551 911 DRL, ENH, AM
20040315 2453079.59 440 NDR
20041001 2453279.902 540 DRL, ENH
20041007 2453285.92 601 NDM, ENH
20041008 2453286.883 308 DRL, ENH
20041106 2453315.805 569 NDM, AM
20041107 2453318.865 644 DRL
20041109 2453319.804 826 NDM, NNS, DWK, CFW
20041110 2453323.814 481 DRL, AM
20041114 2453343.765 365 NDM, AM
20041204 2453387.538 590 NDM
20050117 2453388.676 308 NDR
20050118 2453405.537 357 NDM
20050204 2453412.604 115 ENH, NDM
20050211 2453414.551 211 ENH, NDM
20050213 2453426.567 498 NDM, DRL
20050225 2453433.527 317 ENH, NDM 41
Table A.1: Journal of Observations
Date (YYMMDD) Heliocentric Julian date ADU Observers
20050304 2453443.525 242 ENH, NDM
20050314 2453445.581 576 NDR, NDM
20050316 2453465.553 287 KSB, DRL
20050405 2453649.889 152 ENH, NNS
20051006 2453673.913 224 NDM,IJM,ENH
20051030 2453685.864 290 NDM
20051111 2453712.749 441 GBT, NDM
20051208 2453722.755 308 NDM,IJM,/ENH
20051218 2453750.72 379 NDM
20060115 2453757.689 540 NDM
20060122 2453759.696 640 NDM
20060124 2453768.703 378 ENH, DRL
20060202 2453773.609 650 NDM, ENH
20060207 2453781.589 1019 DRL
20060215 2453785.65 683 KSB
20060219 2453788.688 394 NDM
20060222 2453799.558 203 KSB, NDR, AG
20060305 2453802.571 619 NDM
20060318 2453814.541 526 NDM, ENH
20060320 2453841.541 738 NDM
20060416 2454043.855 1273 DRL, NDM
20061104 2454049.763 326 NDM
20061110 2454060.815 803 GBT, ENH
20061121 2454061.81 416 NDM 42
Table A.1: Journal of Observations
Date (YYMMDD) Heliocentric Julian date ADU Observers
20061122 2454089.76 548 NDM
20061220 2454103.711 400 NDM,SJR,AMR
20070111 2454111.698 299 NDM
20070118 2454118.658 258 ENH
20070203 2454134.596 194 NDM
20070205 2454136.598 182 NDM
20070208 2454139.612 182 ENH, NDM
20070308 2454167.532 401 ENH, NDM
20070308 2454167.542 329 ENH, NDM
Observers: CLM: Chris Mulliss, DCK: David Knauth, NDM: Nancy Morri- son, AM: Anatoly Miroshnichenko, KSB: Karen Bjorkman, TLS: Tracy Smith, PAO:
Patrick Ouellette, HR: Howard Ritter, WJF: Will Fischer, JPW:John Wisniewski,
JT: Josh Thomas, ENH: Erica Hesselbach, NDR: Noel Richardson, NNS: Nick Sper- ling, DWK: Dan Kittel, DRL: Doug Long, AG, ACG: Amanda Gault, SJR: Sara
Rother, AMR: Adam Ritchey, IJM: Ian McGinnis Appendix B
Radial Velocities of Carbon II lines
Table B.1: Radial Velocity of Carbon II lines at 6578
A˚ and 6582 A˚
Heliocentric Julian date RV C II 6578 A˚ RV C II 6582 A˚
HJD CII 6578 CII 6582
2450488.623 28.5 22.7
2450504.557 24.6 26.4
2450505.562 23.8 24.1
2450518.575 23.1 27.6
2450519.588 24.2 20.5
2450527.533 27.1 27.2
2450527.536 25.4 25.1
2450779.824 24.5 20.2
2450798.745 24.4 23.7
2450800.776 28.2 23.3
2450827.658 21.2 19.4
2450847.619 20.6 23.0
43 44
Table B.1: Radial Velocity of Carbon II lines at 6578
A˚ and 6582 A˚
Heliocentric Julian date RV C II 6578 A˚ RV C II 6582 A˚
2450851.622 20.5 23.0
2450852.603 22.2 22.7
2450859.587 20.6 22.1
2451144.808 20.0 20.4
2451145.783 18.8 19.3
2451149.793 18.6 18.8
2451156.756 24.5 24.6
2451157.723 23.7 23.1
2451159.766 21.3 21.8
2451162.733 14.5 16.4
2451163.722 17.4 16.5
2451208.573 25.3 26.6
2451208.579 26.6 22.7
2451208.585 24.5 27.2
2451219.643 19.7 19.2
2451220.637 22.7 22.7
2451223.608 20.3 20.5
2451224.565 18.8 18.6
2451225.627 24.0 25.4
2451231.56 22.2 21.8
2451232.541 26.0 26.0
2451232.55 25.5 25.5
2451239.536 17.4 19.6 45
Table B.1: Radial Velocity of Carbon II lines at 6578
A˚ and 6582 A˚
Heliocentric Julian date RV C II 6578 A˚ RV C II 6582 A˚
2451242.516 19.8 21.6
2451250.539 21.0 20.5
2451250.547 22.7 20.6
2451252.527 19.3 19.8
2451254.521 23.5 21.7
2451257.523 20.1 19.2
2451261.526 18.5 18.9
2451478.851 26.7 24.5
2451479.825 17.4 20.2
2451480.869 23.3 21.1
2451490.804 23.4 24.8
2451491.793 21.6 20.9
2451497.81 23.9 24.6
2451498.829 17.4 17.6
2451500.796 21.2 18.7
2451501.812 21.3 21.8
2451510.77 16.5 14.7
2451512.768 24.8 23.9
2451523.754 20.3 21.7
2451568.729 21.1 21.7
2451829.87 22.8 23.2
2451847.8 25.0 19.3
2451853.879 20.9 18.1 46
Table B.1: Radial Velocity of Carbon II lines at 6578
A˚ and 6582 A˚
Heliocentric Julian date RV C II 6578 A˚ RV C II 6582 A˚
2451901.735 26.1 23.7
2451918.706 22.8 23.7
2451918.711 23.3 20.7
2451919.75 23.4 24.3
2451920.787 22.7 22.0
2451930.675 23.8 22.4
2451935.659 19.3 19.7
2451937.604 21.8 21.7
2451951.568 24.0 23.8
2451953.666 17.2 19.1
2451959.627 23.9 22.8
2451961.625 20.4 22.5
2451962.606 20.3 21.9
2451962.618 19.5 21.9
2451964.518 18.7 19.1
2451968.594 20.3 20.7
2451970.607 22.3 25.4
2451972.594 17.6 19.0
2451976.599 20.9 22.5
2451979.578 25.6 25.7
2451980.597 21.4 20.1
2451986.632 25.4 25.8
2451987.601 18.9 20.2 47
Table B.1: Radial Velocity of Carbon II lines at 6578
A˚ and 6582 A˚
Heliocentric Julian date RV C II 6578 A˚ RV C II 6582 A˚
2451991.575 18.3 22.0
2451991.611 22.1 21.6
2452219.784 30.2 28.8
2452225.825 20.2 19.2
2452235.801 20.9 21.1
2452236.828 22.0 20.0
2452264.748 26.5 24.4
2452265.701 19.7 20.5
2452294.656 27.4 28.7
2452296.671 24.5 23.8
2452299.635 21.4 22.6
2452301.624 22.3 24.4
2452302.603 22.0 25.4
2452307.613 23.2 23.3
2452308.627 19.7 22.2
2452310.609 23.7 21.7
2452311.577 19.9 21.0
2452313.597 15.7 18.2
2452314.569 21.2 21.3
2452315.515 19.8 21.7
2452319.582 18.9 21.4
2452320.576 16.8 18.5
2452323.597 23.6 22.8 48
Table B.1: Radial Velocity of Carbon II lines at 6578
A˚ and 6582 A˚
Heliocentric Julian date RV C II 6578 A˚ RV C II 6582 A˚
2452324.63 22.3 25.1
2452328.529 21.2 21.0
2452330.54 25.6 26.8
2452335.522 22.1 22.3
2452340.557 23.7 24.0
2452344.521 22.5 20.8
2452364.556 22.5 20.6
2452615.765 16.9 14.1
2452623.658 22.9 20.1
2452646.735 32.8 48.1
2452657.713 37.8 61.8
2452661.626 34.4 46.5
2452669.69 18.7 23.0
2452670.644 17.8 15.6
2452676.624 18.7 22.4
2452684.601 14.1 6.9
2452690.584 13.3 16.1
2452691.651 13.2 16.7
2452697.573 15.1 14.1
2452701.57 13.0 10.6
2452705.567 21.5 22.5
2452709.529 13.3 10.0
2452712.536 16.9 18.7 49
Table B.1: Radial Velocity of Carbon II lines at 6578
A˚ and 6582 A˚
Heliocentric Julian date RV C II 6578 A˚ RV C II 6582 A˚
2452713.581 18.8 24.2
2452714.579 22.0 27.3
2452722.557 16.5 21.3
2452952.847 13.1 7.4
2452964.793 17.4 12.9
2452964.805 13.6 11.9
2453044.537 28.5 35.1
2453047.611 12.8 10.3
2453054.612 15.7 14.3
2453062.602 15.9 17.7
2453064.524 17.6 15.0
2453064.569 16.8 15.2
2453074.564 26.9 33.8
2453074.608 20.2 17.4
2453075.551 17.8 18.0
2453079.59 22.8 23.8
2453279.902 22.8 24.2
2453285.92 17.1 20.1
2453286.883 19.8 17.5
2453315.805 19.2 18.0
2453316.819 23.2 19.5
2453318.865 19.4 18.2
2453319.804 13.6 14.2 50
Table B.1: Radial Velocity of Carbon II lines at 6578
A˚ and 6582 A˚
Heliocentric Julian date RV C II 6578 A˚ RV C II 6582 A˚
2453323.814 8.9 4.0
2453343.765 12.7 6.2
2453387.538 23.1 22.4
2453388.676 18.5 15.0
2453405.537 23.8 27.1
2453412.604 20.0 17.7
2453414.551 18.4 19.1
2453426.567 18.3 23.7
2453433.527 22.7 26.5
2453443.525 24.4 26.8
2453445.581 18.1 24.1
2453465.553 18.8 21.2
2453649.889 16.5 15.7
2453673.913 22.1 21.2
2453685.864 19.7 17.9
2453712.749 14.5 13.5
2453722.755 21.8 15.8
2453750.72 25.1 18.7
2453757.689 23.8 22.6
2453759.696 17.9 17.4
2453768.703 24.2 18.4
2453773.609 23.4 21.8
2453781.589 20.3 23.6 51
Table B.1: Radial Velocity of Carbon II lines at 6578
A˚ and 6582 A˚
Heliocentric Julian date RV C II 6578 A˚ RV C II 6582 A˚
2453785.65 21.1 23.9
2453788.688 24.4 24.5
2453799.558 21.8 21.7
2453802.571 13.9 10.5
2453814.541 22.9 28.0
2453841.541 26.9 29.3
2454043.855 21.0 21.8
2454049.763 19.9 17.8
2454060.815 19.9 18.0
2454061.81 24.5 17.9
2454089.76 24.4 28.2
2454103.711 44.3 41.9
2454111.698 22.6 25.5
2454118.658 15.0 15.4
2454134.596 35.7 34.4
2454136.598 24.0 28.3
2454139.612 32.6 44.0
2454167.532 24.5 28.4
2454167.542 35.9 53.6 Appendix C
Radial Velocities of Hα lines in absorption
Table C.1: Radial Velocity of Hα lines in absorption
Heliocentric Julian RV of absorption RV of absorption RV of absorption
date line negative (km s−1) line center (km s−1) line positive (km s−1)
2450488.623 n/a
2450504.557 24.3
2450505.562 12.1
2450518.575 27.2
2450519.588 0.3 43.9
2450527.533 7.7
2450527.536 7.2
2450779.824 29.5
2450798.745 9.2
2450800.776 1.8
2450827.658 -4.5
52 53
Table C.1: Radial Velocity of Hα lines in absorption
Heliocentric Julian RV of absorption RV of absorption RV of absorption
date line negative (km s−1) line center (km s−1) line positive (km s−1)
2450847.619 -5.9
2450851.622 0.8
2450852.603 5.1
2450859.587 6.2
2451144.808 n/a
2451145.783 n/a
2451149.793 -91.2
2451156.756 n/a
2451157.723 n/a
2451159.766 n/a
2451162.733 63.6
2451163.722 61.4
2451208.573 -94.7 5.4
2451208.579 13.4
2451208.585 3.6
2451219.643 21.1
2451220.637 27.1
2451223.608 -80.2 -9.1
2451224.565 -12.7
2451225.627 -92.2 -11.5
2451231.56 29.1
2451232.541 22.2 49.4
2451232.55 31.1 54
Table C.1: Radial Velocity of Hα lines in absorption
Heliocentric Julian RV of absorption RV of absorption RV of absorption
date line negative (km s−1) line center (km s−1) line positive (km s−1)
2451239.536 28.9
2451242.516 21.3
2451250.539 9.4
2451250.547 8.5
2451252.527 8.9
2451254.521 9.7
2451257.523 6.8
2451261.526 14.0
2451478.851 -91.2 2.2 94.4
2451479.825 -92.7 79.4
2451480.869 -102.8 77.1
2451490.804 -10.9 41.0
2451491.793 -83.2 -10.9
2451497.81 22.9
2451498.829 25.5
2451500.796 31.1
2451501.812 30.6
2451510.77 -12.8
2451512.768 -4.4
2451523.754 12.3 73.4
2451568.729 5.2
2451829.87 26.1
2451847.8 8.1 55
Table C.1: Radial Velocity of Hα lines in absorption
Heliocentric Julian RV of absorption RV of absorption RV of absorption
date line negative (km s−1) line center (km s−1) line positive (km s−1)
2451853.879 21.5
2451901.735 14.8
2451918.706 -72.0 11.3
2451918.711 -79.1 9.8
2451919.75 6.6
2451920.787 13.1
2451930.675 21.1
2451935.659 12.6
2451937.604 20.3
2451951.568 5.7
2451953.666 -5.3 21.0
2451959.627 -95.7 53.0
2451961.625 -82.8 -35.1 43.7
2451962.606 -37.7
2451962.618 -39.2
2451964.518 -80.8 -19.0
2451968.594 -79.7
2451970.607 -74.2
2451972.594 -69.8
2451976.599 -58.1
2451979.578 -84.0 -2.7 47.9
2451980.597 -84.0 54.2
2451986.632 -77.0 0.3 100.8 56
Table C.1: Radial Velocity of Hα lines in absorption
Heliocentric Julian RV of absorption RV of absorption RV of absorption
date line negative (km s−1) line center (km s−1) line positive (km s−1)
2451987.601 -81.5 4.3 102.4
2451991.575 -55.5 -4.3 100.7
2451991.611 -60.1 -3.8 104.0
2452219.784 6.0
2452225.825 4.5
2452235.801 7.0
2452236.828 9.1
2452264.748 -1.9
2452265.701 0.8
2452294.656 -21.9
2452296.671 -4.7
2452299.635 -1.0
2452301.624 6.6
2452302.603 8.5
2452307.613 -1.7
2452308.627 -2.2
2452310.609 -13.3
2452311.577 -6.2
2452313.597 -1.8
2452314.569 -0.4
2452315.515 -0.6
2452319.582 -78.0 13.2
2452320.576 12.2 57
Table C.1: Radial Velocity of Hα lines in absorption
Heliocentric Julian RV of absorption RV of absorption RV of absorption
date line negative (km s−1) line center (km s−1) line positive (km s−1)
2452323.597 9.9
2452324.63 13.1 59.7
2452328.529 -2.0
2452330.54 1.5
2452335.522 n/a
2452340.557 n/a
2452344.521 -14.6 57.3 86.3
2452364.556 26.2
2452615.765 -99.8 -7.3
2452623.658 -101.2 -14.5
2452646.735 -16.0
2452657.713 -13.2
2452661.626 2.4
2452669.69 n/a
2452670.644 n/a
2452676.624 -8.7
2452684.601 n/a
2452690.584 -26.2
2452691.651 -33.0
2452697.573 -11.6
2452701.57 -0.6
2452705.567 -11.5
2452709.529 -10.8 58
Table C.1: Radial Velocity of Hα lines in absorption
Heliocentric Julian RV of absorption RV of absorption RV of absorption
date line negative (km s−1) line center (km s−1) line positive (km s−1)
2452712.536 -103.3 -18.4
2452713.581 -104.3 -22.6
2452714.579 -104.2 -17.2
2452722.557 -11.1
2452952.847 -3.6
2452964.793 -129.4 8.6
2452964.805 -120.1 12.8
2453044.537 -27.3
2453047.611 -110.3 12.4
2453054.612 4.4
2453062.602 -126.7 11.2
2453064.524 24.6
2453064.569 22.1
2453074.564 18.6
2453074.608 25.4
2453075.551 28.1
2453079.59 -121.2 23.6
2453279.902 -56.6
2453285.92 -52.2 -20.9
2453286.883 -19.7
2453315.805 -80.0 45.5
2453316.819 -68.7
2453318.865 -0.6 59
Table C.1: Radial Velocity of Hα lines in absorption
Heliocentric Julian RV of absorption RV of absorption RV of absorption
date line negative (km s−1) line center (km s−1) line positive (km s−1)
2453319.804 26.5
2453323.814 15.6
2453343.765 n/a
2453387.538 -9.2 37.9
2453388.676 -0.2 40.3
2453405.537 14.7
2453412.604 12.0 40.6
2453414.551 23.7
2453426.567 -109.5 15.5
2453433.527 13.5
2453443.525 5.8
2453445.581 -2.7 28.4 57.4
2453465.553 5.2
2453649.889 -75.2 -29.1 -7.0
2453673.913 3.2 86.5
2453685.864 22.0
2453712.749 10.5
2453722.755 13.1
2453750.72 -35.5 -5.8
2453757.689 -3.6 42.2
2453759.696 10.5 36.6
2453768.703 19.3
2453773.609 36.4 60
Table C.1: Radial Velocity of Hα lines in absorption
Heliocentric Julian RV of absorption RV of absorption RV of absorption
date line negative (km s−1) line center (km s−1) line positive (km s−1)
2453781.589 38.8
2453785.65 35.4
2453788.688 32.6
2453799.558 36.2
2453802.571 21.4
2453814.541 -2.2 24.8
2453841.541 3.8
2454043.855 -200.2 -91.3
2454049.763 -194.8 -72.5 66.1
2454060.815 -102.5 37.3
2454061.81 -96.1 38.8
2454089.76 40.0
2454103.711 47.3
2454111.698 -5.7 40.5
2454118.658 27.8
2454134.596 36.6
2454136.598 7.0
2454139.612 32.2
2454167.532 -63.5 -27.9 23.7
2454167.542 -10.8 Appendix D
Radial Velocities of Hα lines in
Emission
Table D.1: Radial Velocity of Hα lines in Emission
Heliocentric Julian date RV of emission line negative RV of absorption line positive
HJD Radial Velocity negative (km s−1) Radial Velocity positive (km s−1)
2450488.623 69.7
2450504.557 -59.2
2450505.562 -61.8
2450518.575 -63.7
2450519.588 -71.8 120.1
2450527.533 -76.6 88.5
2450527.536 -73.2 84.9
2450779.824 -50.0
2450798.745 -105.2 101.0
2450800.776 80.2
2450827.658 98.4
61 62
Table D.1: Radial Velocity of Hα lines in Emission
Heliocentric Julian date RV of emission line negative RV of absorption line positive
2450847.619 71.7
2450851.622 100.2
2450852.603 -97.2 95.1
2450859.587 99.0
2451144.808 -22.0 79.0
2451145.783 -43.5 73.2
2451149.793 -42.4 58.4
2451156.756 -62.5 68.2
2451157.723 -51.1 67.9
2451159.766 -47.5 65.3
2451162.733 -33.9
2451163.722 -45.1
2451208.573 -57.6 72.6
2451208.579 -52.6 72.2
2451208.585 -51.5 71.2
2451219.643 N/A
2451220.637 -47.0
2451223.608 -51.7 83.6
2451224.565 -40.2 74.1
2451225.627 -60.5 76.4
2451231.56 -49.6
2451232.541 -48.2 92.2
2451232.55 -48.0 70.1
2451239.536 -57.3 63
Table D.1: Radial Velocity of Hα lines in Emission
Heliocentric Julian date RV of emission line negative RV of absorption line positive
2451242.516 -66.8 119.6
2451250.539 -55.1 107.1
2451250.547 -54.7 109.8
2451252.527 -55.3 104.7
2451254.521 -56.8 96.5
2451257.523 -56.8 88.1
2451261.526 -72.6 92.0
2451478.851 -27.7 41.0
2451479.825 -23.7
2451480.869 -42.0
2451490.804 N/A
2451491.793 N/A
2451497.81 114.1
2451498.829 -73.4 105.8
2451500.796 -56.8 NA
2451501.812 -52.7 113.2
2451510.77 N/A 86.0
2451512.768 N/A
2451523.754 -68.8 48.8
2451568.729 -100.7 117.3
2451829.87 -62.5
2451847.8 -68.8 90.0
2451853.879 -68.9 103.4
2451901.735 -62.3 46.6 64
Table D.1: Radial Velocity of Hα lines in Emission
Heliocentric Julian date RV of emission line negative RV of absorption line positive
2451918.706 -54.9 85.5
2451918.711 -47.2 85.4
2451919.75 -59.4 43.6
2451920.787 -59.8
2451930.675 -70.8 102.2
2451935.659 -85.6 85.8
2451937.604 -58.6 103.8
2451951.568 -84.2 104.3
2451953.666 -59.7 118.9
2451959.627 -49.9 93.4
2451961.625 -81.3 124.9
2451962.606 N/A
2451962.618 N/A
2451964.518 -44.2 102.6
2451968.594
2451970.607 N/A
2451972.594 N/A
2451976.599 N/A
2451979.578 -48.4
2451980.597 -49.9
2451986.632 -44.3 83.2
2451987.601 -40.1 58.9
2451991.575 N/A 48.6
2451991.611 N/A 50.4 65
Table D.1: Radial Velocity of Hα lines in Emission
Heliocentric Julian date RV of emission line negative RV of absorption line positive
2452219.784 -60.6 82.5
2452225.825 -66.6 76.5
2452235.801 -64.9 71.5
2452236.828 -61.6 123.9
2452264.748 -68.6 91.2
2452265.701 -61.8 90.9
2452294.656 -70.9 79.3
2452296.671 -73.6 75.1
2452299.635 -67.0 71.1
2452301.624 -61.5 69.7
2452302.603 -53.9 73.3
2452307.613 -75.2 79.7
2452308.627 -67.0 77.4
2452310.609 -93.9 77.0
2452311.577 82.8
2452313.597 -67.4 89.3
2452314.569 -57.7 101.3
2452315.515 93.9
2452319.582 -52.9 115.8
2452320.576 -47.8 110.6
2452323.597 -42.3 99.4
2452324.63 -39.9 94.3
2452328.529 -67.7 89.9
2452330.54 -50.3 87.7 66
Table D.1: Radial Velocity of Hα lines in Emission
Heliocentric Julian date RV of emission line negative RV of absorption line positive
2452335.522 -29.6 72.3
2452340.557 -30.7 25.6
2452344.521 -82.3
2452364.556 -52.2 97.3
2452615.765 -43.1 74.8
2452623.658 -67.4 85.8
2452646.735 -80.5 71.5
2452657.713 -69.8 60.7
2452661.626 -63.0 42.7
2452669.69 -52.1 63.5
2452670.644 -50.0 58.6
2452676.624 -64.3 75.7
2452684.601 -55.9 69.1
2452690.584 -77.9 60.8
2452691.651 -89.0 64.9
2452697.573 -74.9 88.0
2452701.57 -72.8 107.1
2452705.567 83.8
2452709.529 97.5
2452712.536 -93.1 89.3
2452713.581 -90.9 84.8
2452714.579 -81.8 83.7
2452722.557 -91.3 73.3
2452952.847 -88.3 87.8 67
Table D.1: Radial Velocity of Hα lines in Emission
Heliocentric Julian date RV of emission line negative RV of absorption line positive
2452964.793 -62.3 108.9
2452964.805 -57.9 98.8
2453044.537 -64.8 97.5
2453047.611 -67.4 109.8
2453054.612 -70.9 89.8
2453062.602 -60.9 99.0
2453064.524 -59.2 106.9
2453064.569 101.5
2453074.564 -61.3 96.3
2453074.608 -56.3 112.9
2453075.551 -58.1 116.1
2453079.59 -54.9 100.9
2453279.902 74.9
2453285.92 N/A 57.4
2453286.883 N/A 55.0
2453315.805 N/A 96.6
2453316.819 102.6
2453318.865 97.7
2453319.804 -40.2 100.2
2453323.814 -33.4 101.6
2453343.765 -43.1 85.0
2453387.538 -64.8 98.1
2453388.676 -65.0 101.6
2453405.537 -65.6 68
Table D.1: Radial Velocity of Hα lines in Emission
Heliocentric Julian date RV of emission line negative RV of absorption line positive
2453412.604 -55.6 104.8
2453414.551 -59.8 122.9
2453426.567 -63.2
2453433.527 -69.6 116.8
2453443.525 -62.9 129.1
2453445.581 -64.4
2453465.553 -86.5 95.3
2453649.889 -62.3 76.4
2453673.913 -51.3 51.1
2453685.864 -51.6 112.5
2453712.749 -57.3 104.6
2453722.755 -56.9 103.0
2453750.72 -71.7 83.2
2453757.689 -59.9 115.2
2453759.696 -58.4 104.5
2453768.703 -49.7 85.9
2453773.609 -44.2 121.8
2453781.589 -44.7 71.6
2453785.65 -58.6 110.1
2453788.688 -57.0 76.0
2453799.558 -51.4 97.4
2453802.571 -56.5 113.4
2453814.541 -61.8 95.0
2453841.541 -76.7 102.3 69
Table D.1: Radial Velocity of Hα lines in Emission
Heliocentric Julian date RV of emission line negative RV of absorption line positive
2454043.855 N/A 92.7
2454049.763 -30.3
2454060.815 -41.5 117.5
2454061.81 -35.7
2454089.76 -58.9
2454103.711 -38.3
2454111.698 -61.5 85.5
2454118.658 -50.2 134.1
2454134.596 -34.3 105.7
2454136.598 -64.2 71.4
2454139.612 -48.4 124.8
2454167.532 76.3
2454167.542 86.7 References
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