Got questions? We’ve got answers! Below we address the most common queries relating to Getting Started, Technical & Observing, Tools & Resources, and Community & Research.
Getting Started
What is the AAVSO? The AAVSO is a community of people who are passionate about variable stars. Founded in 1911, they have been taking data for over a hundred years and have made it available for free so that it can be used by anyone to contribute to science.
Do I need a telescope to participate? You don’t! All you need is your eyes and a little practice to take measurements of variable stars. We have a tutorial you can follow to learn the basics. It’s a great place to start even if you want to do digital observing in the future?
How do I join? Start by registering for a free website account. From there you can become a paying member.
What is an obscode and how do I get one? In order to submit data to the AAVSO, you must first register for an obscode. You can do this by logging in, going to your settings and clicking on “Request an Obscode.”
Do you have a newsletter and if so, where do I sign up? Yes we do! We have an email newsletter called “AAVSO Communications,” which is published on the first Tuesday of each month. It has information on a variety of things including events, interesting stars, and active campaigns. You can sign up for this and a variety of other subscriptions from the Email Settings tab of your profile.
There is so much information, I’m not sure where to start. This is something many AAVSOers (as we like to be called) struggle with. There is a lot to learn, but we recommend taking it slow. In fact, we have a page dedicated to Getting Started to help people with exactly this.
Technical & Observing
I’m having trouble logging in. First try resetting your password. If you have not logged in a long time (over a year) you may not have an account in our new system. In this case please sign up again using the email address we have on file and your information will automatically be linked. If this doesn’t work or you have more questions, please contact us.
How do I reset my password? First go to the login screen. Then click on “Reset Password” and follow the instructions.
I used to be a part of the AAVSO and would like to rejoin. We are happy to have you back! All you need to do is sign up for a new account. If you already have an obscode, let us know and we will connect it to your account.
I’m afraid to submit because I don’t know if my observations are any good. You are not alone. This is something that most observers struggle with. One of the easiest ways you can check is to take a popular star, do the reductions and see how they compare to others (you can use the LCG for that). You can also take a CHOICE Course on the method of your choice. Or, if you are a paying member, you can request a mentor.
What are transformation coefficients and do I need them? Every observational setup is slightly different and these differences in instrumentation can affect the measured brightness of your stars. Transformation coefficients allow you to correct for these differences. It is a lot of work but it is strongly recommended as your data will be much more comparable with that of other observers.
What filters should I be using? If you are buying new filters, you should get a mixture of Sloan and Johnson, e.g., uBVriz. If you have some existing programs, you should keep using the filters that you have been using in order to keep consistency. You can discuss this and other technical issues on the Instrumentation & Equipment forum.
I am unable to post/add pictures to a forum post. The forums give you more privileges the more you use them. This might seem annoying, but there is a good reason for it as it protects us from being subject to large amounts of spam posts. If you find you cannot do something that others can, please contact us and we will fix this for you.
There are several different types of data you can submit. What’s the difference? Great question! This is quite complicated, but the simple answer is that we currently accept four distinct data products:
- Variable Star Photometry: Measurements of brightness changes of an object over time.
- Exoplanet Photometry: Time-series data that follows the change in light as an exoplanet goes in front of its host star.
- Variable Star Spectroscopy: This is data taken on a star that separates the light into its constituent wavelengths. It can give us valuable information about the stars composition.
- Solar SunSpot data: This is data taken by eye of the number of sunspots visible on the sun any given day.
What do all of the different “Observing Types” mean? If you want to submit observations on variable stars to the AID you do have a lot of choices. Here are the current categories and a brief description of each.
- Visual: These are by eye observations with or without the use of a telescope.
- CCD: Originally this was for monochrome observations with a charge couple device. It now refers to any monochrome device, including CMOS
- DSLR: Observations with a color camera. In these the pixels have filters that are literally painted on.
- PEP: data taken with a photo-electric photometer. They allow for high-precision but are difficult to find as they are no longer in production.
Tools & Resources
How do I plot a light curve? There are a lot of ways to answer this question. This simplest is to use the Light Curve Generator, our interactive plotting tool. If you want to plot more data than just ours, VStar is a great tool which plots light curves and has several other functions as well.
What is a star chart and how do I make one? A star chart is a visual representation of the sky around the star you wish to observe. It’s a great tool for finding the star in your field as well as appropriate comparison stars. We make this very easy with the use of our Variable Star Plotter (affectionately known as VSP). This gives you a variety of stuff.
Do you offer any classes? We offer quite a few classes on a wide variety of topics in our CHOICE Course series.
How do I learn to make observations? This is a question many new AAVSO observers ask and the first question you have to ask yourself is what kind of observations do you want to make?
If you want to learn visual observing, we provide an introductory tutorial. If you want a deeper dive on visual or other form of observing, we offer manuals and a selection of CHOICE courses. And we’ve uploaded observing-related how-to videos to our YouTube channel.
Do you have a list of tools available? We do! Please check out the Application Portal for a mostly comprehensive list.
Do you offer mentors? We do have mentors available to AAVSO members. Learn more about the benefits of becoming a member.
Community & Research
What data do you have and how do I access it? We have a significant quantity of data, some of which dates back more than 100 years. Our main user-contributed databases are:
- AID: Variable Star Photometry
- AVSpec: Variable Star Spectroscopy
- AED: Exoplanet Transits
- Solar: Sunspot Counts
The top three can be found using the Global Search Tool. Solar data may be accessed through the LASP website. We also have a variety of other data available.
I want to use AAVSO data in a publication. How do I cite it? All of our data is free to use with an acknowledgement. We also encourage you to offer co-authorship if an observer’s data was particularly useful. Our full policy can be found here [Data Policies].
How do I connect with other observers? Individual users can be found using our Find a Member tool. If you would like to connect to a group of like minded observers try looking into our Special Interest Groups.
Why should I become an AAVSO Member? AAVSO members get exclusive access to specific observing tools, engaging programs, and special interest small groups. Our international community provides support and access to resources that provide data and results used by professional astronomers and observatories. Check out our AAVSO Membership page for more information.