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A: They're still alive, if you're feeling nostalgic you can go and play with Galaxy Zoo 1 and Galaxy Zoo 2. However, your clicks will no longer be recorded in our database.
A: Science isn't always pretty! While the HST publicity team typically put out big beautiful images, a lot of the science with HST images concentrates on the little blobs in the background. As we are doing real science here, we can't ignore them. The field of view of the camera we use is so small that even the biggest surveys don't get large numbers of bright galaxies, but they do get tens of thousands of small, faint objects. While they don't look much, they are a glimpse back to the early stages of galaxy formation, when the universe was only half its present age.
A: For now, we need to make sure that each of our classifiers is seeing exactly the same image. We’ll be experimenting with adding this feature in the future.
Much of the extra information was provided by the Sloan Digital Sky Survey themselves, rather than by us here at Galaxy Zoo. We know how important it is for many of you that you get to explore after classifying, and so over the next few months we'll be adding as many of these features back as possible. In the meantime, please use the forum to tell us what you'd like.
The galaxies in Galaxy Zoo: Hubble are drawn from several large surveys completed with the Advanced Camera for Surveys. So that we can compare the results from Galaxy Zoo 2 and Galaxy Zoo: Hubble we've included a selection of images from Sloan. You can find out more about these surveys on their individual webpages.
Galaxy Wars — which asks people to compare two galaxies to see which has the most prominent bar or spiral arms — will be back shortly. Deciding which galaxies qualify for wars takes a lot of work, and we didn't want to make you wait for everything else until we were ready.
A: The previous version of the site allowed users to look at data provided by the Sloan Digital Sky Survey while classifying; this caused confusion because we only want you to classify according to what you can see. Let computers take care of the rest! However, you can now find a link to this extra data on the 'My Galaxies' page which is linked from the main analysis page if you’re logged in.
A: If you’d like to change your mind during classifying a particular galaxy, you can restart the process by clicking the 'Restart Classification' button. Once you’ve finished a galaxy, and your classification has been submitted to our database, then you can’t change it, but don’t worry – we compare classifications from multiple users so someone else will correct any mistakes.
A: It is not possible to redo a classification, as we want each one to be independent. Allowing classifications to be replaced would open up the possibility of classifiers discussing objects and changing their classifications to agree with one another. This would reduce our ability to understand the uncertainties on the classifications. However, don't worry about our final results: each galaxy has been looked at by many people, so on average the classification is likely to be correct, and occasional mistakes don't matter.
A: If one person does the classification – even if they’re an expert astronomer – then anything odd or interesting can be blamed on them. With multiple independent classifications we can statistically calculate the confidence in our classification, and that’s a large part of the power of Galaxy Zoo.
A: Well spotted. Massive stars are blue, and also short lived (by astronomical standards, anyway) so we only see them where star formation has occured recently. That tends to be in spiral galaxies, but beware! We're trying to classify galaxies by shape, not by colour; one of the major results from Galaxy Zoo is that colour and shape are more independent than people believed, so we need to be careful. Classify what you see and ignore the colours!
A: We tested for any difference in classifications between showing people colour and showing people monochrome images in the original Galaxy Zoo, and found that it was only small. We also discovered that our users really like looking at coloured galaxies, and we aim to please.
A: Please always classify the one that’s right in the middle, but use the ‘is there anything odd’ question and the tag system (when it is live) to tell us about anything interesting that catches your eye.
A: Sorry. Really, we're sorry. The team is growing, but is still small and busy, and we're rushed off our feet making the most of your results and developing the Zoo. You might find an answer on the forum. The forum is also the best way to grab our attention.
A: Sadly, astronomers are very attached to catalogue numbers, so there's no way we can officially name them. Sorry!
A: Objects that move away from us appear redder than if they were stationary. Likewise, objects get bluer if they move towards us. This is called the Doppler effect. But that does not mean that all red things are moving away from us, because somethings just are red anyway (like some stars) and some galaxies emit blue light, for example. So we have to be careful with colours! You actually need to look at their spectrum to be sure if it is moving away from you.
