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Eurêka !

Brian Marsden (1937-2010) was director of the Minor Planet Center from 1978. Document Harvard-Smithsonian CfA.

What to do if you discover something unusual in the sky ?

While today the chance to discover a small celestial object remains high, in practice due to their very low magnitude most of them require large telescopes. So, to define the limits of our scope, this quest does not address to the million galaxies not identified yet or the Integrated Flux Nebulae (IFN) but mainly to the new asteroids and comets as well as to new possible nebulae. Indeed, to discover such objects all you need are amateur instruments properly equipped, e.g. an apochromatic refractor, a Rich Field telescope, an astrograph or a large (> 250 mm of aperture) fast reflector equipped with a CCD and a guiding system, all being fixed on a sturdy equatorial mount.

If you do like rigorous science and if you feel you have found something unusual in the sky, here is what you have to do.

1°. Look for errors and artifacts

In number of circumstances what you think to be a new celestial object is nothing else than a known celestial body or worse an artifact in your optical system. So prior any diffusion on official channels and to preserve your honesty and your mental health double check your observation to suppress any artifacts that could come from  your instrument or observation method (scope, eyepiece, film or CCD, image processing software...).

Take specially care to "blops" on a picture that look like stars but which are not. Suspect ? I had the occasion to be disconcerted by these artifacts analysing a picture of M81 and I had to request the intervention and skills of the astronomer Pierre Kolher at that time at Observatoire de Paris to put an end to the debate.

Look for the presence of this feature on a similar picture taken at another time. Today with the widespread of Internet many on-line professional catalogs can quickly confirm your feeling. The USNO-B1.0 stellar catalog for example displays about one billion stars down to magnitude 21.

Without to forget numerous amateurs books and atlases on CD-ROM's (likeRealSky constitued of 120 CDs but today this item is out of stock) showing hundreds of millions stars and deep sky objects.

To get ephemerides, recent astronomy programs called "Planetarium" come today on several CD-ROM or can be directly downloaded from Internet providing you a standard database more or less complete. Most of these programs can optionally access to complementary external databases that you can download free of charge or buy separately. The next programs do an intensive usage of additional databases and are used by asteroïds and comets chasers among other users :

Except "The RealSky" which consists on databases on CD-ROM's linked to various Planetarium software, all these programs are able to display objects of your choice down to inaccessible magnitudes to amateur scopes (21), except after long expoures.

Like Nova for Windows to name one famous application, all these software also display trajectories of artificial satellites, comets, asteroids and Kuiper objects, in fact they are only limited by your computer memory and the update or not of your data files. 

Your suspicious object can also be something unusual but already referenced here and there for some days. Asteroids in particular are probably the first objects that you can confuse with stars. Fixed in front of the starry field for dozen of minutes you need an accurate and a high resolution sky chart to identify them.

Then make the preliminary astrometric measurement to confirm the position of the object. Two programs can be used :

- Astrometrica developped by Herbert Raab

- CCD Astrometry by John Rogers (seems no more available)

Both require reference data from the Hubble Guide Star Catalog. In addition, these programs automatically format data for an electronic submission to the Minor Planet Center.

At last, since 2005 there is also the MPO Canopus software (see below) that many advanced amateurs use. When you pull up a plate-solved image of a star field, it is able to identify all of the catalogued asteroids, and show their path over a 1-hour period. In addition, it can also be connected to a telescope, and perform photometry.

If you think have located an asteroid, check first the coordinates of the suspect object on the Minor Planet Checker or Minor Planet & Comet Ephemeris Service website at Harvard CfA.

Before going further, check also the recent news on the major associations websites devoted to these activities. Asteroids, comets and some other moving bodies are reported to the International Astronomical Union, IAU;  novae and supernovae also or to the American Association of Variable Stars Observers, AAVSO, its foreign representatives and on the website of the International Supernovae Network, ISN.

At last you will never discover a new nebula or a remote galaxy because all them are probably catalogued until some far distance - a few nebulae are hidden or are so hard to find in stars clusters or dusts clouds that only the more powerful telescopes have a chance to drive them out. For galaxies the question is even no more in the hands of amateurs or even of grounds observatories but rather an affair reserved to large space telescopes.

Now, with all these data in hands you can know with certainty the origin of your suspect object.

2°. Get confirmation of your observation

Once your observation is confirmed "on paper", i.e. the object you have found is NOWHERE plotted, take some time to get confirmation in situ. If you are member of an astronomy amateur association contact a well equipped and experienced friend to help you validating your observation.

Sometimes this process cannot be completed has it depends on the weather factor. So do not hesitate to contact the responsible of a well-known foreign association that could confirm your observation under better sky conditions. Today Internet through its email and webcam services is the fastest way to contact someone at antipodes at a near light speed. Facebook and Skype are very fast mean to contact your friends.

If you want to be the discover of something new you must be the first to confirm the novelty. Using Internet in less than 6 hours you can get your answer. Use the slow Earth rotation to foresee the best places in which other amateurs could confirm your observation. Look first behind you where it is still night.

To download : PIXY System 2

Freeware to help you identifying any suspect object

To read : Hunting Asteroids From Your Backyard, Dennis Di Cicco

At left, recording of 4 new asteroids discovered in a 25' field in Taurus on 24 December 1995 by Dennis Di Cicco. He used a Meade LX200 of 400 mm f/10 equipped with a CCD camera SBIG ST-7 and an Optec MAXfield focal reducer yielding the relative aperture to f/3.3. It is a stacking of three-minute exposures. At right, the astrometry and photometry MPO Canopus software (50$) able to identify any asteroïd on a digital picture, and so by extension, all moving "dot" not cataloged yet.

Imagine that you have observed a suspect object last night in Europe (23h GMT). In place of sleeping you do a first check and you send your confirmation request to a US friend in the morning at 4 AM (TZ GMT-5 on US East coast or TZ GMT-8 on the Pacific coast, this is still the night on all USA, except Hawaii). Do not call your Japanese or Australian friend because he could not confirm your observation before ten hours, when it will be locally night (Japan is in TZ GMT +9. On the other side, a Japanese can ask you to confirm his observation).

With chance your correspondent can look for your suspect object immediately and reply with all details some hours later, in the first lights of the sunrise in Europe.

The ideal is to find a correspondent who can access to a public or professional observatory registered to IAU, like the Observatoire du Cégep or Mégantic in Québec, what insures it a quasi professional status and a greater credibility.

Then there are two possibilities. Your observation is not confirmed. In that case you have to request new observations from your friend in the "dark side" of the Earth, this time in Japan or Australia. Send him your email as soon as possible and at the latest early in the afternoon. Ask him to use the same instrumentation as you (at least the same magnification) or that he follows the same procedure to record the image or to process it. Send him by email print screen or any file showing the place of your suspect object among the other stars in order he had some points of reference. Complete your email with all necessary explanations that you will judge useful about your object concerning its magnitude, possible move, etc.

Some amateurs are also in relation with professionals astronomers or subscribed to dedicated maillists. This is a very efficient method to get an immediate confirmation of a discovery.

If this is not the case and your object disappeared or is well plotted in some catalogs, you lost your night but in return you gained experience. Remember that it exists few amateurs able to find several new celestial objects each year. To be the first is a very hard task which requests much rigor and motivation in which professionals are also your concurrents... (professionals usually discover new celestial bodies two months before amateurs...).

3°. Send your observation

If you have successfully passed through all these steps, if your experienced friend calls you back and confirms your suspicions, congratulation, you have probably discover something new !

Without hesitation it is time now to prepare your email and alert in the CBAT with the certitude they will not tell you to clean up your eyepiece or worst you did a mistake...

Central Bureau for Astronomical Telegrams

The CBAT webpage highlighted here has information about how to properly report a possible discovery, including an online report form and links to check services as the ones listed above.

Then it is the discoverer's responsibility to follow the confirmation and reporting procedures as outlined by the CBAT. Following those procedures does not guarantee your find will be an actual discovery. But it will ensure that you and your report are taken seriously. 

The care in that field is preferable than too much impressments. The quickest way to gain a reputation as a crank is to submit a half-passed report without taking the time and making the effort to eliminate all other possibilities than a new object. Worse, this lack of rigor should reduce to nothing the reputation of the amateurs community, specially the perseverance of some amateurs trying to make a rigorous work with professionals. Take care.

Good luck !

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