What do I do when I discover a new variable star?

当我发现一颗新变星，我该如何做？

We get that question a lot at AAVSO headquarters, and it deserves a detailed answer.  It’s always exciting to discover a new variable star on your CCD frames, or from your nightly observations.  Although discoveries of novae and supernovae often get more coverage, the discovery of less prominent variables can also have benefits for scientific research.  Many thousands of variable stars are known to exist, but it’s likely that there are many millions more waiting to be discovered from the collected data archives of the amateur and professional observing community.  So what should one do in the happy event that you discover what you think is a new variable star?

我们从AAVSO总部得知，这个问题非常普遍，当然也值得仔细回答。从你的观测中发现新变星是个令人激动的事情。虽然变星比新星和超新星的光变幅度小，但是也很有科学价值。我们知道有成千上万的变星，其中绝大多数还等待人们去发现。那么我们如果发现一颗自认为的变星，该如何处理呢？

Check the catalogs

查对星表

The very first step of course is to verify that it is indeed new, that it hasn’t been discovered as a variable by some other observer or survey.  The first place to look is the AAVSO’s International Variable Star Index, VSX.  This is the AAVSO community’s online repository of known variable stars, collected by the community from a number of different sources.  The General Catalogue of Variable Stars is included, but many tens of thousands more variables are also included from a number of different sources.  It’s a good bet that if a variable star is known and being actively observed, it’s in VSX.  When you go to VSX, you should have a good astrometric solution for your CCD images, and know the position of the variable to within an arcminute at least.

首先要做的工作是确定你发现的是不是真的新变星。推荐访问VSX，这是AAVSO维护的一个相对比较全面的数据库，包括变星星表GCVS以及其他各种渠道得到的得到充分观测的变星数据。你需要从你的CCD图片中获得星体坐标，至少精确到角分精度，然后去VSX查询。

As a secondary source, you can also double check several other online catalogs.  Doing so might be useful if the star is present in another star catalog (such as the Guide Star Catalog, or 2MASS), but might not be known as a variable.  This is especially useful for checking to see if the object is a nova or large amplitude star like a Mira.  If it’s present in another catalog in a similar bandpass but with a much fainter magnitude, that lends weight to the possibility that it is indeed variable.  You can search any number of catalogs using VizieR.

其次需要查对的地方是其他星表，比如GSC或者2MASS，你需要查对该星是否在这些星表中存在并是否标识为变星，这用于排除是否是新星或者类似薴藁增二型长周期大幅度变光变星。如果在这些星表中确实存在对应，但是在类似的滤镜波段情况下，星表中的对应星很暗，那很可能就是新变星了。你可以访问VIZIER来查对。

Another good practice is to make sure it’s not a solar system object!  The solar system is full of asteroids, many of which can easily reach the brightness range available to amateur telescopes.  You can search for possible solar system objects if you know the postion and the time of observation to good precision by going to the Minor Planet Center’sNEO Checker.

另一个重要的工作是排除太阳系内天体！排除小行星，你可以到MPC的相关网站去查对是否是个小行星正好盖在你的可能新变星位置上导致误判。

Check your data

检查你的数据

Yet another check is to make sure there are no problems with the image itself.  Some image defects like cosmic ray hits should be obvious as such — they’ll often have a jagged or blocky appearance in contrast to round star images on the frame.  Bright moonlight or terrestrial light sources can also introduce ghost images or glints on your images.  More subtle effects can sometimes occur.  One example is residual charge: if you take an image that saturates a bright star, some charge may be left over at the position of the saturated object on several subsequent frames.  The result will look like a fading star on subsequent frames.  You should have a good feel for what your data say, and more importantly what they don’t say!

当然，你需要确认不是你的CCD出现了问题。排除宇宙射线之类的东西，排除月光或者地景光造成的可能鬼影等等。举例来说，有一种现象是，当你刚拍摄一张亮度较高的过饱和星点后，由于所谓的残留电荷的问题，导致可能你之后拍摄的几张照片中，在相同位置会留有残留影像，会导致误判，总之小心点，玩CCD的都应该知道这事。单张照片很难下结论的。

One last caveat is beware unfiltered observations!  Many observers have had variable star “discoveries” turned into false alarms by making unfiltered observations with CCD cameras.  Many different types of variables are red in color, and will have red magnitudes far brighter than the V or visual magnitudes reported in many catalogs.  CCD camera systems have much stronger response to red light, and so unfiltered observations of red objects will make them seem much brighter when compared to a bluer field or comparison star.  Be extremely careful when assessing variability based on unfiltered data; a good rule to follow is that unfiltered photometry is only useful for observing objects that aren’t red (i.e. have B-V < +0.7 or so). 

最后一个忠告是小心使用无滤镜观测！许多报告的可疑新变星发现最终都因为可能是由于使用非滤镜观测而造成的误判。很多类型的变星在红色波段比其他V波段以及目视波段亮很多，CCD的红色波段响应比其他波段的也强，所以非滤镜观测这些红色星会比星表中的蓝色星等亮很多。所以使用非滤镜观测在做判断的时候一定要仔细小心。最好不要用非滤镜观测那些红色的变星（比如，去观测那些B星等减去V星等小于+0.7的变星）

Is it a nova or supernova?

检查是否新星或者超新星

If you think you’ve discovered a nova or supernova, the first place to report it is the International Astronomical Union’s Central Bureau for Astronomical Telegrams — follow the instructions on that page to make your report.  This will ensure that your discovery will reach the largest number of people as soon as possible, and will also make it easier for other observers to confirm your discovery.

如果你认为你发现了一个新星或者超新星，请首先报告给IAU的CBAT—在他们的网页上填表上报。这将会使你的报告在尽快的时间内得到更多人知晓，当然也就会让别人能更快的证实你的发现。

If your object is confirmed as a Galactic nova or bright extragalactic supernova, it will be added to the AAVSO’s database of objects in short order, but we require that it be confirmed by the IAUC as a nova or supernova before announcing it as such.  In rare circumstances we will announce objects that have been submitted to us first if they are exhibiting interesting behavior that requires rapid announcement.  However, it is strongly preferred that observers begin the process of reporting novae and supernovae with CBAT first.

如果你的上报被证实是系内新星或者系外超新星，你的发现将会在极短的时间内添加到AAVSO的数据库中，但是我们只有在IAUC正式宣布你的发现后才会这么做。只有在极少数情况下，比如很特殊的类型或者需要迅速观测的目标，我们才会提前发布我们收到的报告，在默认情况下，请先上报给IAUC。

Submitting to VSX

上报给VSX

The AAVSO International Variable Star Index (VSX) was designed from the beginning to be an easy and straightforward tool for observers to search for known variable stars as well as to submit new variable star discoveries.  You’ll need to do a few things in order to submit your star to VSX:

AAVSO的国际变星索引（VSX）是一个平台，可以很容易的验证查询已知的变星以及上报自己新的发现。以下几项是你上报时需要做的：

• You need to register for VSX
• 你需要先注册VSX
• You need to read the submission guidelines for VSX
• 你需要阅读VSX的上报指南
• You need to know the position of your variable to an accuracy of a few arcseconds (at least), either by doing your own astrometry, or by identifying the object from an existing astrometric catalog (e.g. USNO)
• 你需要得到目标的精确坐标（至少精确到角秒），你需要自己做好天文测量。
• You need to know if the object appears in any other photometric or astrometric catalogs (e.g. Tycho, Guide Star Catalog, 2MASS, USNO-A or -B, or others)
• 你需要知道是否这个目标出现在其他的照相或者天体测量星表中（比如Tycho, Guide Star Catalog, 2MASS, USNO-A or -B或者其他的星表）
• You need to create a light curve of your data clearly showing the variability (for example, an X-Y plot made with Excel or any other spreadsheet or plotting program)
• 你需要建立一个变光曲线来显示它的变光（比如，用EXCEL或者其他电子表格软件绘出的直角坐标图）

Once you’ve registered for VSX and logged in, you can then go to the “Submit” page, and follow the instructions on either the “New Star Form” or “New Star Wizard” links.  With these tools, you can submit information about your variable to VSX moderators.  These volunteers will look over your submission and determine whether your object is (a) correctly identified, (b) is variable, and (c) is previously unknown.  If so, you will be notified that your submission was approved, and your object will appear in VSX.  You’ll receive similar notifications if your submission is rejected, or if the moderators require more information to properly assess your submission.

一旦你注册了VSX并登陆进去，就可以进入到提交页面，你可以按照“新星表格”或“新星向导”的指令进行操作。用这些工具，你可以向VSX负责人提交有关你发现的变化的信息。这些志愿者会审查你的提交并且决定你所发现的物体是否是（a）正确的（b）亮度变化的（c）未知的。如果是这样，你将会被通知，你的提交通过了。你所发现的目标就会出现在VSX上。如果你的提交被拒绝，或者负责人需要你更加准确的信息来完善你的信息，你也会收到类似的通知。

Note that for those of you who are planning on writing a paper on your observations and would like to keep your data confidential, you may keep the supporting observations private, but the star’s identity will be made public as soon as you submit it to VSX.  We encourage you to submit your objects as soon as you discover them, but please be aware that the community will at least be aware that your variable star exists as soon as you submit it to VSX, even if they can’t see your data.

请注意，如果你计划将你的发现写成论文并希望你的数据保密，你可以不上报后续观测数据。但是该变星的身份将会在你提交到VSX时公布于众。我们鼓励你一发现就提交，但是你必须明白，你的变星在你提交后就已经被委员会人员所知，即使他们没有看到你的后续数据资料。

 

Publish your results

出版你的发现结果

All observers should be proud of the work that they do in discovering new observations, and an important part of the scientific work of variable star observing is sharing your observations with the community.  One aspect of this is reporting your observations to the AAVSO, and you can do this as soon as your star is approved and entered into VSX.  Another important aspect of variable star observing is publication — sharing your work in a formal way with the astronomical community through publication in a research journal.  There are a number of journals that astronomical researchers use to learn about new discoveries, and the AAVSO has its own journal for variable star research — the Journal of the AAVSO.

所有的观测者都应该为所进行的发现而感到骄傲，并且向大众分享有关变星的部分科学工作也是非常重要的贡献。为做到这些，你可以报告你的观测数据给AAVSO，当然也可以在一些比较正式的天文机构杂志中发表论文来公布你的研究。有大量的杂志便于天文研究者去学习有关新发现，AAVSO也有自己的有关变星研究的杂志—the Journal of the AAVSO.

If you’ve discovered a new variable, you can write a paper about your discovery observations either before or after you submit to VSX.  Purely observational papers are acceptable, and you do not need to be an astrophysicist in order to create a paper of value to the community.  For example, you could easily create a paper detailing the circumstances of your discovery, your observing procedure, your observations and their analysis, and the results of your data analysis.  Often, such a paper contains all the information another researcher would need to duplicate your results, and if need be to either derive important physical information about the star or to determine what future observations are needed to obtain such physical information.

如果你已经发现了一个新的变星，你可以在提交到VSX前或后写一篇有关你发现数据的文章。我们更愿意接受单纯的观测的文章，你没有必要像一位天体物理学家那样去创作一篇有份量的文章给委员会。比如，你可以写篇有关你的发现的详细情节，发现的步骤，你的观测数据，和分析以及你数据分析的结果。通常情况，这些信息就是其他研究者如果需要去重点探究该星的物理信息及要决定未来的观测是否需要时所需要了解的信息。

If you have not written a paper before, you should read through the materials from the AAVSO’s Publication Workshop held during the 95th Spring Meeting in 2006.  The presentations and other workshop materials are available here.  When you submit your paper to the Journal of the AAVSO, it will be read by the editor, and if accepted for consideration it will then be sent to a referee who will make a recommendation as to whether it should be published.  Again, your paper does not need to be comprehensive, but it should be as complete as you can make it given the data that you have.

如果你以前没有写过文章，最好先浏览一下来自于2006年第95届春季大会所举办的 AAVSO’S Publicacion Workshop 的一些材料。一些与会展示材料和其他的研讨会材料点击这里。当你提交你的文章给JOURNAL of the AAVSO时，编辑会进行审核，如果被采纳，将会送往审查人（专业文章鉴定专家)做一个推荐看是否予以出版。请记住，你的文章无需全面综合，但必须详尽的包含你所有的数据。

If you are interested in writing a paper on your discovery, we encourage you to read recent articles in the Journal of the AAVSO.  If you’re not yet familiar with variable stars and their classifications, we encourage you to learn more about the subject.  Two good introductory texts are Percy’s “Understanding Variable Stars”, and Sterken & Jaschek’s “Light Curves of Variable Stars”.

如果你对写有关发现的文章感兴趣，我们建议你读一下近期的文章。如果你对于变星和他们的种类（分类）还不清楚，我们建议你多学些有关这方面的知识。有两个比较好的文章推荐给你Percy’s “Understanding Variable Stars理解变星”, and Sterken & Jaschek’s “Light Curves of Variable Stars变星的光变曲线”.

For more information

更多信息

The AAVSO community is very diverse, and there are many people who are interested in variable stars and enthusiastic about helping new members and observers learn more about variable stars and doing variable star research.  There are a number of community resources you can take advantage of if you feel you need more information:

AAVSO协会是多样性的，在这里有很多人对变星很感兴趣并且热心帮助新会员去发现和学习有关变星，并且做一些研究工作。如果你需要更多信息，这里有许多你可以利用的资源，

• The AAVSO Data Mining Section — researchers who mine existing data sources to obtain new variable stars and variable star data
• aavso-discussion — our online discussion group for all conversations relating to the AAVSO and variable stars
• aavso-photometry — our online discussion group for topics specifically related to photometry
• AAVSO headquarters (note that it may take some time before one of our limited number of staff members can respond to your request)