FAQ
 
 

Why I can't find anything?

You may have set search filter. Try to deselect the checkbox.
If you are a novice click on Catalog tab and choose one from catalogs and lists.
You can use the Search box on the left, or advanced search. In this case, pay attention to the fields, in particular RA and Dec and set a proper search radius. If you do not want to look for a field, you must not put any value.
To see complete data, click the "View" link at left of the listing.

What makes the search field "Search" on the left bar?

It will be searched by:
  • WDS catalog: coord_2000, discov_num e comp fields;
  • common and alternative names of the stars;
  • Bayer designation, with greek letters (alpha, alp) and constellation code (UMa), name, latin name and genetive;
  • Flamsteed numbers and constellation code (UMa), name, latin name and genetive;
  • Henry Draper catalog (HD);
  • HR catalog;
  • Hipparcos catalog (HIP);
  • SAO catalog.
You can search a specific catalog using the catalog code first. For example, to search for Sirius write: SAO 151881 -or- HR 2491 -or- HD 48915 -or- HR 2491; or just Sirius.
If you need more search options, use the "Advanced Search" found in "Catalog" tab.


How do I replicate filters in searches?

If for any reason you do not want to use the filters and want to replicate the search functions using the Advanced Search, go to the Database tab or click on the action "Advanced Search" under the search box found on the top-left of each page.
  • Instrument Limit

    Sets the separation according to Dawes formula = 120 / D, where D is the instrument's diameter.
    Example: 0.6 (C8), 1.3 (Megrez 90), 1.5 (80ED)
  • Orbit known

    Set Orbit = Y (checked)
  • Common name

    Set Common name = "not void" on the option menu
To learn how data is looked up in the selection or segments (left on the Catalogs tab) click on "Search Again" after selecting an option.
Note that the research carried out through the action list are not viewable through research as they require a special programming.


Can I sort my results?

It depends on where one is. All lists that have emphasized the description of the column (with links) can be ordered. The first click sorts in ascending order, the second click in descending order, the third order according to the "natural" or to advance. In ascending order up an arrow appears next to the name of the column, descending a down arrow. If it is not expected that there is an ordering of the columns are not clickable. This is true, for example, the list of other components of the system in "Remarks" or on the list of the ephemeris in the calculation of orbital elements.
You can sort one column at a time.


How many arcsecs are two stars separated?

Inside each Observations form, look at the separation datum. "Sep now", rho, is the latest known separation (actually calculated if orbit is known, latest official measure otherwise).
To know if a companion star is the main, consider that in the WDS catalog the main star is called A: find the pairs AB, AC, AD and so on. Reading the separation column in the list of system's components you'll know what the components are separated.
Another way to know the distance to nearby stars is to look for a double using the Search command on the left bar, and once inside the menu tab select neighbors. Here are a series of near double as a table and map: in the table's last column is shown the separation in degrees.

What is the meaning of the columns in the list of components of a system or a list of search results?

The lists have the standard columns with the following meaning:
common_name: the name of the principal star, the Greek letter Bayer or Flamsteed catalog number
coord_2000: WDS field of RA and DEC (see WDS)
# or discov discov_num: WDS field of the discoverer of discovery and progressive
comp: component in the system (blank if single pair)
first: date of the first measurement made
last: date of the last measurement made
obs: number of observations recorded
sep: separation of the first components: current orbit if known, otherwise the last measured
mag1: magnitude of the primary
mag2: magnitude of the secondary
d_mag: difference (delta) of magnitude between primary and secondary
Reports: number of reports included in the site


Why in "My Doubles" or "In this session" does not list anything?

The reason is that you're new, or just logged in, or you did not clicked any double since you logged.
You must login to be recognized by the system, and access to these functions.
Even if you set the checkbox "Remember me" at login, after a certain time you're idle (a few hours) you're logged out: when you resume working on the site, you're reconnected automatically, a new session is created, and previous session data is lost.


There's no more action "My Doubles" or "Limits" filter

Please login. Your session is over.


Why do it says the diameter of the instrument is not set?

If you go to the Setup tab you can set the Instrument and Diameter fields. The first is used to automatically insert the name of the telescope when creating a report, the diameter (or aperture) to be able to filter only the pairs your instrument is able to separate.
If you do not enter the diameter, the filter "Limit instrument" is not active.


I entered in the Setup tab my telescope's parameters and Dawes limit is displayed, but in a double the system tells me that is not separable.

The algorithm is based not only on resolving power, the ability of separation (filter limit instrument), but also on the difference of magnitude (filter limit viewing).
For example, Sirius would be within the reach of virtually any instrument (sep.> 8 ") but it is very difficult to split because of the enormous gap in magnitude between the two components.


I can't filter out systems I'm not interested to. I wish to list doubles from 1.5" down to 1.33".

Well, generally speaking you can use Advanced Search selecting "between" option and separating using a comma (between=1.5,1.33). Alternately, you can filter out systems you can't separate in Advanced Search when in "Separation" choose "Less than" and enter 1.5 in the field to set top limit. Then, check "Limit to Scope" to set bottom limit. This way we simulate the "between" option. It goes without saying you have to setup your telescope's diameter in Setup->Preferences tab and, of course, be logged in.


When I click the checkbox at login "Remember me" if I take up does not recognize me.

Possible reasons: 1. you were logged in from another computer, 2. you click on "Exit", 3. you have deleted cookies from your browser, 4. your browser does not accept the setting of cookies, 5. your browser is set to erase all data, including cookies, at the end of each session.
It is necessary that your browser accepts cookies from this site to ensure that the function memory will operate.


How observations are entered?

First of all you must be logged otherwise not enter anything. If you do not have an account, you must create it.
Once logged in, look for a double and enter its form: on the left choose the action "New Report" If a visual observation, "New Measure" if it is a measure instrumental (for example, the analysis software Reduc).


How do I exit the "Remember Me" and no longer be automatically logged in?

Click the Logout link on the top bar on the left.


I see pages very bad, the characters overlap or can not click or the pages are poorly formatted.

This site was created to be used with the Mozilla Firefox browser and the pages are XHTML 1.0 Transitional compliant, certified by the W3C. Change your browser.


Why don't you implement feature XYZ ?

If you pay me...