Beautiful Image of New Supernova in M82

M82_SN_Arrow

This morning Adam Block, Manager of the Mt. Lemmon Sky Center observatories, sent me a message with a beautiful image of M82 that shows the bright supernova. Adam is a world-renowned astrophotographer who has won many awards for his work. He used the Mt. Lemmon Sky Center 0.81-meter telescope to take the image data to create his LRGB composite images. The powerful telescope is part of SSON and is available to all users for their own imaging and research projects.

Here is Adam’s message to me this morning verbatim, which includes the links to his latest images:

“here is my “press release” (meaning I send this to a small group of interested people)

Supernova!

I apologize if the following isn’t terribly well written… it is now quite early in the morning having just completed acquiring and processing data on M82 and its new supernova! It isn’t a perfect image (quick put together)… but here is what I got:

http://skycenter.arizona.edu/gallery/Galaxies/M82_Supernova

(click on the image for a larger version, click on the thumbnail for a version with an arrow!)

The direct links to the images are:

http://skycenter.arizona.edu/sites/skycenter.arizona.edu/files/M82_SN.jpg

and with the ARROW:

http://skycenter.arizona.edu/sites/skycenter.arizona.edu/files/M82_SN_Arrow.jpg

I look forward to showing guests to the SkyCenter a view of this through the telescope. Keep in mind this image is stretched in its brightness; the supernova is considerably brighter than any part of the galaxy and as it brightens it may outshine billions of stars in M82.


http://skycenter.arizona.edu
http://mirrorlab.as.arizona.edu
—-
Caelum videre iussit, et erectos ad sidera tollere vultus.
He bid them look at the sky and lift their faces to the stars.
–Ovid, Metamorphoses 1. 85-8″

Trying Remote Astronomy with the Sierra Stars Observatory Networks

Dr. David Galbraith started using SSON in April of 2013. He is the Head of Science at the Royal Botanical Gardens in Burlington, Ontario Canada and an active member of the Hamilton Amateur Astronomers (HAA). David wrote an article for the January issue of the  HAA online magazine Event Horizon with the title: Trying Remote Astronomy with the Sierra Stars Observatory Network.

It is a well-written and informative description of David’s experience using SSON and why he chose our network for his remote astronomy projects. If you are interested in trying out remote astronomy and want to read about one of our user’s experience trying out SSON, you can read David’s article here on the HAA web site.

– Rich Williams

Analyzing Comet Lovejoy

By Rich Williams

Figure 1

Figure 1 Comet Lovejoy

Last night I was able to fit in an hour’s worth of imaging time to get some data on Comet Lovejoy (also called C/2013 R1) on the SSO telescope just before the end of twilight. The comet is quite bright and were it not for all the media coverage of Comet ISON, which reaches perihelion on Thanksgiving days two day from now, Comet Lovejoy would probably be getting much more attention.

I scheduled six 240-second images without a filter (clear) and six 120-second images for B, V, and R filters. My original intent was to combine the data to create a LRGB composite color image (Figure 1). However, using various image processing techniques to analyze the image data I found some very interesting structure in the coma and tail of the comet.

One of the difficulties in working with comet image data is the great range of brightness between the area near the coma and the outer edges of the tail. Standard stretching of the images in various settings from very low to very high helps see more, but still a lot of the detail in the data is overpowered and hidden. I use MaxIm DL to analyze this type of data. Two image processing techniques that really help bring out fine detail in comet structure are digital development and rotational gradient filters.

Digital development processing does a nice job showing both bright areas and dim areas in objects like comets simultaneously. Figure 2 is a 24-minute total exposure (six four-minute stacked images) of the comet processed with digital development. It shows a lot of fine interesting detail around the coma and the tail. Most of the detail is not visible in raw data because it is overpowered.

Lovejoy-C-digital

Figure 2. Digital development processing of Comet Lovejoy.

A rotational gradient filter enhances low contrast structure radiating around the coma and in the tail. Figure 3 is a 12-minute total exposure (six two-minute stacked images) taken with an R filter. I then created the movie below from the six images processed with the rotational gradient filter to see if I could discern any movement in the comet’s structure. The series of images were taken between 12:43 and 13:11 UT on 11-26-2013 UT date. In just under a half hour span I didn’t expect to see much, if any, movement. To my surprise the comet is very dynamic and the undulating of the tail in such a short span of time is readily apparent.

Lovejoy-R-rotational

Comets are fascinating objects to observe. They change considerably from day to day and, as I found, even from minute to minute. I look forward to doing more of this work on Comet Lovejoy and of course Comet ISON, if it survives its close encounter with the sun on Thanksgiving Day.

 

Comet Lovejoy dynamics over a 29-minute period

Comet Lovejoy dynamics over a 29-minute period

 

Telescopic Observing Labs at Mesa Community College

One of the reasons I founded SSON was to make professional observatory facilities readily available to teachers and students. I saw an opportunity for teachers to use a network of remote telescopes regularly for astronomy class lab work and research. Several colleges and universities use SSON for these types of programs. Knowing they have access to our network of telescopes throughout the year ensures they can plan to use our facilities with confidence and get great results.

The following guest blog by Kevin Healy highlights how Mesa Community College uses SSON for their astronomy courses.

– Rich Williams

Telescopic Observing Labs at Mesa Community College

by Kevin Healy

The astronomy program at Mesa Community College (www.mesacc.edu/departments/physical-science) offers two introductory astronomy courses: one focusing on the Solar System and the other focusing on stars and galaxies. Each of these courses can be taken with or without the accompanying laboratory course.

As part of both of our lab courses, we introduced modern telescope imaging during the Spring 2012 semester. These lab exercises have provided students with the opportunity to plan telescopic observations and then use their requested images to look for asteroids or KBOs and construct color composite images of deep sky objects.

Our “Telescopic Observing” module involves two exercises completed in different lab periods. The first lab exercise introduces students to basic concepts of astronomical imaging such as the meaning of pixel values and image coordinates and the processes of image set alignment and color compositing.

At the end of this first exercise, students select two targets to be observed with a telescope in the Sierra Stars network. Their first target is a moving Solar System object while the second target is a Messier object. While I choose the exposure times and filters used for each object, the students must ensure that their chosen targets are up during darkness. This part of the planning is performed with the use of planetarium software, star atlases, star wheels, and/or the JPL Horizons “What’s Observable?” website (http://ssd.jpl.nasa.gov/sbwobs.cgi).

Lab instructors collect the observing targets and send them to me for telescope scheduling. In a typical semester we have 10 lab sections. Student groups of 2-3 mean that approximately a dozen Solar System objects and a dozen Messier objects are chosen. With the automated catalog search within the SSON website interface, scheduling these observations is quick.

For Solar System targets, I use 30-minute or 1-hour intervals between 30 second exposures (for asteroids) or 60 second exposures (for KBOs). Students have successfully identified many of the main belt asteroids and the larger KBOs.

For Messier targets, I typically use BVR or BGR filter sets for star clusters and galaxies with exposures in the range of 30-60 seconds per filter. This is enough to give the students enough detail to work with the images. If a student group selects a nebula, I typically add a longer H alpha exposure to replace the R filter image.

In the second lab exercise, students process their image sets. For the Solar System object image set, this involves aligning the stars in the images to look for motion against the star field. The Messier object image set is used to construct a color composite. We then ask students to present their final images to the other student groups. Each student is responsible for providing at least one fact about the Solar System and Messier object.

Students enjoy the hands-on activities and they see how real astronomical observing and image processing is done.

The image below is a composite of stacked images of the asteroid 32 Pomona taken Oct 25/26, 2012 at SSO. The asteroid is visible as a chain of 5 points in the center of the image. Each image was a 30-second exposure. The 5 exposures were spaced apart by 1 hour. They were added together to the form the final image. This is an excellent illustration of how an asteroid moves relative to the background star field. It is one of many examples of how I use SSON as a learning tool for my students.

Asteroid 32 Pomona Sequence

Asteroid 32 Pomona Sequence

 

headshot-20120920-square

 

 

 

 

 

 

 

 

 

 

 

Dr. Kevin Healy
Residential Astronomy Faculty
Mesa Community College
Mesa, AZ

I am astronomy instructor and planetarium director at Mesa Community College in Mesa, Arizona. While the Arizona skies are often clear, the Phoenix metro area presents an obstacle to observing more than a few very bright objects. The SSON telescopes provide the opportunity for students to collect images they cannot get from our roof-top telescopes here at MCC. These images allow our introductory astronomy students a taste of astronomical imaging. I am very excited about the new opportunities for spectroscopy and for southern hemisphere observing made possible through a lot of hard work by the staff of the SSON telescopes.

SSON Update on Comet ISON

By Rich Williams

I took a series of 180-second exposures of Comet ISON using the Sierra Stars Observatory telescope in California last night (evening of March 4th California time/ March 5th UT date) to see how the comet was behaving. The comet hasn’t shown much of an increase in its brightness or in the length of its tail since my last blog about the comet on February 11. However, it is still out around the orbit of Jupiter and has a ways to go before approaching the sun.

Below is a composite image of Comet ISON created from seven 180-second images for a total of 21 minutes of exposure time. The telescope was guiding on the comet during the exposures. The comet is in the center of the 21 x 21 arc-minute field of view of the image.

Comet ISON March 5, 2013

Comet ISON March 5, 2013

The image below is a zoomed in area of the comet from the image above.

Comet ISON March 5, 2013 -- zoomed in

Comet ISON March 5, 2013 — zoomed in

 

Finally the video below shows the comet moving through a crowded star field in the constellation Gemini. You can see a few galaxies in the images as well. The total time from beginning to end of the sequence is about 40 minutes. The tail seems more apparent in this moving image of the comet.

 

 

 

Comet ISON Video March 5, 2013

Comet ISON Video March 5, 2013

 

Comet ISON Shows Its Tail!

By Rich Williams

I decided to start chronicling the changes in comet ISON as it approaches perihelion and beyond. On the night of February 12, 2013 UT date (Monday night February 11 California start time). I scheduled a series of 12 180-second images of ISON using on the SSO 0.61-meter telescope here in Markleeville, California. The seeing varied between 2.0 to 2.4 arc seconds that night. The telescope tracked on the comet selected from the SSON online MPC database. I downloaded my images from my SSON FTP directory after processing the SSON jobs for the night’s observing run. On first inspection I was delighted to see a discernible tail on the comet. This is pretty cool as the comet was still just beyond the orbit of Jupiter and more than 9 months from its extremely close grazing of the sun when it reaches perihelion. Comets coming out of the Oort are fresh and very unpredictable. Even so I think that an early tail like this is a good sign for a great show this fall and winter.

Comet_ISON_2-12-2013

Comet ISON showing early signs of tail.

I processed the 12 images using MazIm DL to create a movie loop of the series. Other than stretching the calibrated images no image processing was performed on the data. Above is one of the 180-second images of the comet. The field of view is approximately 21 by 21 arc minutes. The magnitude of the comet was approximately 15. The comet, while small, clearly shows a tail in the full image. The image below is a zoomed in cropped area around the comet from the same image.

ISON_2-12-2013-crop

Comet ISON zoomed in view

Finally the video below is a movie loop of the 12 images clearly showing the movement of the comet against the star field over approximately 40 minutes. I will try to image the comet regularly (every week or so weather and moonlight permitting) to monitor the brightness and changes in the comet as it approaches the. Sun. I’ll post my results here on this blog for you to see.

Comet ISON Video 2/12/2013

Learning How to Use the Rigel Transmission Grating Spectroscope (TGS)

By Alessandro Odasso 

The Rigel Telescope Transmission Grating Spectroscope (TGS) system has been made available to the SSON users thanks to the cooperation between Rich Williams and Dr. Robert Mutel (Iowa University). Quoting Rich’s words “The Rigel Telescope TGS system opens up a whole new field of inquiry for students, researchers, and curious people”.

I belong to the third group and I must say that when I first read his blog I was not only curious but also a bit puzzled. I was curious because I knew that the spectrum of a star is like a fingerprint, in a metaphoric sense it’s like the star’s own DNA. I was a bit puzzled because I was afraid that such a system would be too complicated to be used by a user with no specific experience.

During the Christmas holidays I decided to devote some time to read once again the blog and to pay attention to the user manual written by Dr. Mutel and I felt that, after all, it did not sound as complicated as I initially feared.

My first attempt in using the system was aimed at getting the spectrum of Merope, a star belonging to the Pleaides cluster. To do so required me to do two things:

1) I took an image of Merope(30 seconds exposure time)

2) I analyzed the FITS image with two different programs.

Phase 1 – Taking an Image

I decided to use the S filter, the one that has a slit to block out most light except for a narrow strip. You schedule to take TGS images on Rigel just as you do for regular images. However, you need to define two other parameters:

  1. The first parameter, “focus offest” is intended to tell the system which part of the spectrum you want to analyze with greater resolution. Having nothing specific in mind, I chose 402, a value that allows you to observe the H-alpha line with maximum spectral resolution.
  2. The second parameter, “RA offset” is a correction factor intended to have the star displayed on the left side of the image, just a trick to have the elongated black and white rainbow spectrum centered in the middle of the image. Again, not a problem: the manual gives you a very simple formula that calculates the RA offset, already expressed in RA seconds, taking into account the star declination.

Maybe, in the future, the SSON web page could be programmed so that this calculation is done automatically.

There is nothing different about the resulting FITS image. FITS is a standard so you can open the image with whatever FITS viewer, including Astrometrica (by H. Raab): you clearly see the spectrum spreading at the right of the slightly defocused zero-star and you can read the usual details in the FITS header.

Phase 2 – Analyzing the image and displaying the spectrum

My initial attempt to analyze the spectrum in my image was with RSpec, whose trial version can be freely downloaded from the vendor site.

I was impressed with RSpec’s very easy installation and very nice Graphical User Interface. Even without reading the manual, it is straightforward to open the FITS file and you are immediately rewarded by the system that displays a raw, not calibrated spectrum. In other words, the system displays a graph where the Y axis is related to the pixel brightness and the X axis represents the various pixels of the spectrum that you see in the FITS image.

The next step is to calibrate the graph so that the X-axis represents the wavelength expressed in nanometers (or Angstroms). The easiest calibration supported by the program is the one where you simply fill a field telling the system how many Angstroms / pixels must be taken into account. But here I was at a loss; I had no idea about the correct value!

The calibration technique is explained well in the video tutorials provided by RSpec. The idea is to identify a specific spectrum feature by simply clicking on it and by giving it the wavelength that you either know a priori or that you can get by clicking on the correspondent feature of a reference image of a star having a similar spectrum. The nice thing is that RSpec is shipped with a large reference library of star spectra.

As easy as this may seem, when I used the reference spectrum B6IV that should have worked with Merope… again I was at a loss! When I opened the spectrum of the reference image I was unable to compare it with my raw spectrum: the shapes were too different and I couldn’t determine which features matched in the two spectra!

At this point, to be honest, I felt confused. My learning curve was greater than I expected. While this learning process is certainly important, it is a bit frustrating, especially if you are a bit lazy as I am :-)

But here I have good news! Another nice thing about RSpec is that there is a Yahoo RSpec User Group where you can ask for help! This is a place where many technical issues are discussed and clarified. So I joined the forum and I am pleased to say that they helped me immediately sending me a calibration file that was a good starting point.

I guess the reason why RSpec calibration process is not automatic is simply due to the fact that RSpec needs to be very general, the software is not tailored to any specific hardware platform.

Rigel TGS Software for Linux and Mac Operating Systems

When I contacted SSON and Dr. Mutel asking for help calibrating my TGS images, I was given software that is designed specifically for use with the Rigel TGS. Almost no calibration is needed. This software comes in the form of a Python script that requires a Linux installation. I was lucky in this case as I happen to have a dual boot system with Debian installed on my computer.

Before running the script, I had to install a few libraries according to the instructions that I received. The whole installation process took less than 30 minutes and it was straightforward.

The nice thing about the program is that it is able to generate a bitmap showing the calibrated spectrum plus specific spectrum features in a complete automatic way and in just a few seconds!

You do not have to bother about details like, for example, the graph title and exposure time: this information is generated reading the data from the FITS file. Furthermore, you can choose which spectrum features you would like to be highlighted. Finally, the program is able to synthesize a second bitmap image of the colored spectrum rainbow. There is one important input that you must be careful to identify and enter: the zero-star pixel position.

The image below is the Merope spectrum that I obtained a few minutes after the installation of Dr. Mutel’ script:

Merope - 2013_01_06-spec

My experience proved to me that Dr. Mutel’s TGS software program is easy to use. It is only fair to note that when something like this is easy to use the reason is because other people spent a lot of time and effort to design and implement it. We must praise the Iowa and SSON teams for this!

Of course, this new tool does NOT transform us “curious people” into experts! However, thanks to this new tool and with appropriate guidance from professionals we may be in the position to give a little but not negligible scientific contribution in the framework of the so called pro-am collaborations or “citizen science projects”.

_________________________________________________________________________

Alessandro has been an avid SSON user since November 2009. He participates in several astronomy programs and projects. I thank him for giving me his personal experience using the new Rigel remote TGS system and sharing it on my blog.

I also would like to thank Dr. Mutel for his continued excellent work on the Rigel TGS system. He wrote the code for the Rigel TGS Software and continues to enhance it with features such as TGS Stitch, which enables you to combine two or more spectrum data optimized for different wavelengths into a single data graph. It’s very cool and useful!

For those of you who want to run the Rigel TGS software on a Windows system you can install the Ubuntu Linux operating system on Oracle VirtualBox. Both VirtualBox and Ubuntu are free to download. I have this set up on the Windows 7 laptop I’m writing this with. It’s easy to do following the installation instructions for both programs. After setting up Ubuntu (or another Linux OS) on VirtualBox, download the TGS Software and install it according to Dr. Mutel’s instructions.

Here are some links to quickly get you started installing the Rigel TGS Software on your system:

– Rich WIlliams

 

Scientific Astrophotography Book Review

Jerry Hubbell first started using SSON for his astronomy projects in April 2009. Three years later in April of this year Jerry sent me an email message asking if I would be willing to review a draft of an astronomy book he was writing that would be published later this year by Springer for Patrick Moore’s Practical Astronomy Series. The title of Jerry’s book is Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data.

I was very impressed with Jerry’s hands-on approach to the subject and to his excellent presentation and organization. After reading the draft I wrote the following review of the book for Jerry:

Jerry Hubbell has been using SSON since April 2009 for various remote astronomy projects. His new book “Scientific Astrophotography” is a well written, comprehensive description and guide for doing meaningful scientific imaging work in astronomy. Whether you are just starting out or are experienced doing scientific astronomy projects you will find the book to be an excellent reference for improving your skills.

Scientific Astrophotography is a great “How To” book. Jerry takes a somewhat engineering approach to the subject. In the final chapter in the book, Amateur Astronomer Access to Professional-Level Observatories, Jerry wrote a very nice section called Using the Sierra Stars Observatory Network (SSON).

Congratulations Jerry on a job well done! I look forward to reading the next book you are writing.

– Rich Williams

 

Near-Earth Asteroid Toutatis Video


Adam Block took a series of images of the near-earth asteroid Toutatis as it passed close by Earth using the Mt. Lemmon Sky Center Schulman 0.81-meter telescope. The images were taken on December 11 around 7PM MST (2:00 UT December 12).

The video combines 180 5-second exposure images taken back to back. The total elapsed time in the video is 15 minutes. The asteroid was moving quite fast against the background stars at the time!

Adam is the manager of the Mt. Lemmon Sky Center Observatory and oversees the operation of the observatory within SSON.

Thanks for sharing Adam!

– Rich Williams

 

Remote Spectroscopy of a Wolf-Rayet Star Using SSON

Image

Before releasing the Rigel Telescope transmission grating spectroscope (TGS) system for use by SSON users I had to run some tests of the system to ensure it worked well. I chose to run a series of schedules on the Wolf-Rayet (WR) star HD 50896 also referred to as WR6 from the Wolf-Rayet catalog. Wolf-Rayet stars are very rare, only about 500 Wolf-Rayet stars are known in the Milky Way galaxy. They are the massive stars that start out their life with a mass more than 20 times the sun. They are also extremely hot stars with surface temperatures ranging from 30,000 to 200,000 degrees Kevin.

 

WR stars burn through their hydrogen fuel very rapidly ending their lives in a supernova explosion after only a few million years. During their life they eject huge amounts of gas creating a kind of atmospheric shell surrounding the star with a mass that eventually can equal that of the star. The light we see from these stars is actually mostly visible light emitted from the heated, excited ionized gas shell. This is what makes them such interesting objects to study with a spectroscope.

 

As the WR stars evolve towards the end of their life the composition of the gases in the surrounding envelope changes from mostly helium and nitrogen to more carbon and oxygen. This change in composition over time is the reason WR stars fall into two main classifications: WN sequence of stars with broad emission lines of helium and nitrogen and WC sequence stars with broad emission lines of helium, carbon, and oxygen.

 

Although they are extremely hot and bright most of the photon energy released by WR stars is in the form of UV and soft X-ray light, which is what excites the ionized gas in the shell. The only WR Star easily visible to the naked eye is Gamma 2 Velorum, which is a 1.7 magnitude star located in the southern hemisphere. Because the Rigel TGS disperses the light of a star (or other object) you need to image relatively bright objects to achieve reasonable signal to noise ratio data in reasonably short exposure times. For my test of the Rigel TGS automated run I selected the WR star HD 50896 because at a V magnitude of 6.74 it is a fairly bright target for the Rigel TGS to image. The images were taken the night of November 27, 2012 UT, two days before a full moon.

Figure 1. TGS Image of Wolf-Rayet star WR6 taken with SSON/Rigel Telescope

Figure 1 illustrates what the original calibrated FITS files data looks like. I set the SSON schedule to use the S filter on the Rigel Telescope, which is the 600-line TGS filter using a slit to block out all but a slice of the sky around the star. The slit is useful for blocking out extraneous light from nearby spectra in crowded fields. However, the alternate non-slit TGS filter on the Rigel telescope works as well in most cases. The exposure time of the image is 120 seconds. As you can see the stars are deliberately defocused to give a better spread of the dispersion for measurement. The object star is deliberately positioned at the far left side of the image to capture the complete spectrum to the right.

 

After you receive your image spectrum data you need a software program to measure and analyze it. I used an excellent software program called RSpec to analyze my data. It runs on Windows and is easy to learn and use. You can download a fully functional 30-day trial version to try it out before buying.

Figure 2. Spectrum graph of WR6 from data in figure 1 created with RSpec

 

Figure 2 shows the calibrated measured spectrum of the image data in Figure 1. The very strong helium II emission line in the spectrum of the Wolf-Rayet star clearly stands out in the top graph. On the bottom is a synthesized color spectrum of the monochromatic data. One of the reasons I chose a Wolf-Rayet star is because these stars are some of the few stars that show such strong emission lines in their spectrum. The emission comes from the hot excited ionized elements in the gas shell surrounding the star. The spectra of the vast majority of stars primarily show absorption lines that are black caused by colder gas blocking and filtering the light. Figure 3 shows the spectrum of Vega from the data taken with the Rigel TGS that shows many absorption lines (note that the peaks in the graph are inverted compared to the emission lines in the WR spectrum, which point upwards).

Figure 3. Spectrum of Vega measured with Rigel TGS system

Dr. Mutel, the mastermind behind the Rigel TGS system at the University of Iowa, analyzed the spectrum of the same image I did using a Linux-based software program generating a graph very similar to the one I created using RSpec. He overlaid markers for the emission lines of several of the elements that appear prominently in the WR spectrum. You can see the results in Figure 4. It is fascinating that you can read the complex chemistry of a star this way.

Figure 4. Graph of spectrum of WR6 highlighting element emision lines

If you decide to try out the SSON/Rigel TGS system be forewarned that you will have to do a little more work beforehand than you do using the regular photometry and color filters in our system. You need to determine which wavelengths of the spectra you want to optimize and calculate the appropriate offsets. This is explained in the scheduling section of the SSON web site and in the TGS Users Guide that Dr. Mutel wrote, which you can also download from the web site.

 

You have the option to use two TGS filters on the Rigel Telescope. They are identical 600-line TGS filters but one has a slit to block out most light except for a narrow strip. The other filter has no slit and is great for imaging extended objects and getting multiple spectra in a single image. Both TGS filters produce excellent results.

 

The Rigel Telescope TGS system opens up a whole new field of inquiry for students, researchers, and curious people. I look forward to seeing and hearing about how our users take advantage of this great opportunity to do spectroscopy projects remotely using SSON.

 

- Rich Williams