Procedure: Star hopping is a process used to locate objects in the night sky. To star hop, the observer uses well known or well charted bright objects to find his way to a desired object. A predetermined path of bright stars is often drawn up before the observing session. First, you must obtain a star chart so that you can make accurate drawings that you can compare with what you see in the telescope eyepiece or finder scope (read the section on star charts below). The first object on your path should be a naked eye star (one that you can see without the aid of a telescope) near to the intended target. Then pick a number of other objects that provide a clear stepping path toward what you want to see. Things such as patterns of stars in geometrical shapes, pairs of stars that can serve as pointers in a particular direction, and different brightnesses to set off particular stars are acceptable steps to take. Galaxies and quasars are not acceptable as they will be too faint for you to find. When the observing session begins, locate the first star in the night sky. Center the main scope on this star. Then move the telescope to the next object by comparing the view in the eyepiece or finder with the drawings in the chart. This constitutes your first hop. Keep hopping until you get to the object under study.
Where to Start: Start with Polaris, the north star. Choose your hopping path from there, since you will begin your observing by polar aligning the telescope.
Star Charts: Here are some tips for painless star hopping. Each "hop" should move you in the general direction of the final object and should be relatively short in angular size. Hops, if possible, should be done in the finder scope since it provides a wider field and can thus allow a greater grasp of the orientation of objects. However, some objects may be too faint to pick up in the finder so the main scope is still important to use. Make sure that you do not bump your finder scope and cause it to become misaligned with the main scope. Another way to orient yourself if there are not enough stars in the scope to do so, is to remember your coordinate system. If you lock the RA wheel and nudge the scope in Declination, you will be moving either North toward Polaris or South. The stars, since they are fixed, will of course move in the opposite direction. So a nudge in the direction of Polaris will make the stars appear to move toward the South. To determine East and West you could turn of the tracking motor and watch stars drifting toward the West. Then it becomes easy to compare the view from the scope with the star chart.
Understanding Star Charts Star Charts are pages in an astronomical
atlas much as state and city maps are pages in a road atlas. The primary
objects in a star chart are the constellations and the stars contained
within them. The constellations have boundaries as well as unique names,
much like counties on a road map. In addition, a grid is normally superimposed
on the constellations that shows the equatorial coordinate system (RA and
Dec). The RA will be marked of in hours from 0 to 24 mostly along
the bottom and top of the graph and the Dec will be marked off in degrees
from -90 to +90 mostly along the left and right edges of the graph. Most
of the objects placed on the chart will be stars of different sizes representing
different brightnesses. Other objects such as nebulae and galaxies will
have their own symbols. There might also be a few additional lines showing
the apparent path of the sun over the year (the ecliptic) and the plane
of the Milky Way galaxy. A few of the objects will have numbers and
letters that serve as identifiers for those objects. The brightest stars
will have Greek letters that represent Bayer catalog identifiers. They
are placed such that an earlier letter represents a brighter star. For
example, the second brightest star in the constellation Lyra is Beta Lyrae.
Numbers next to a star are from the Flamsteed catalog. They represent an
ordering of the stars within a constellation by increasing RA. Thus the
bright star with the lowest numerical value of RA in the constellation
Orion will be denoted 1 Orionis. The Flamsteed catalog includes fainter
(and consequently more) stars, but there are still many more even fainter
stars with neither identifier. Some of these will have other identifiers
based on other catalogs. Non-stellar objects have two major catalogs to
represent them. The first is the Messier catalog, denoted by a capital
M follow by a number. For example, the Great Nebula in Orion happens to
be M42. This catalog has 110 entries, which are usually the brightests
and more easily seen. A much more complete catalog is the New General Catalog
with about 7800 entries. They are denoted by a capital NGC followed
by a number. Some charts leave out the letters "NGC " to minimize clutter.
So if you see and object that is not a star but has just a number next
to it, it is almost always an NGC identifier. A particularly bright or
interesting object may be included in many catalogs and thus have many
identifiers, but, in general, the oldest identifier is the one that is
most often displayed on the chart.
Using the RA dial to find objects (a shortcut) Instead of going through the sometimes time consuming task of star hopping, a dedicated observer can often locate an object more quickly by properly aligning the RA dial on the telescope. The RA dial is simply a piece on the telescope near the base that has the 0 to 24 hours of subdivided RA printed on it. It is adjustable because the motion of the stars necessitates changing it every time the telescope goes for more than a minute with the motor off (i.e., every day at least). To use the RA dial effectively, polar alignment must be very accurate. A small error in polar alignment will make it nearly impossible to use this technique without further effort. The advantage is that this further effort can still be less than star hopping on some occasions. To align the RA dial, simply center the scope on a bright star near your target for which you know the RA. Then move the RA dial (not the scope) until the pointer on the scope is lined up with number on the RA dial that matches the star's RA. You can check the Dec. of the bright star against what the Dec. is reading on the scope to see if you are correctly polar aligned. (If not, use hte offset method: calculate the difference in RA and Dec between the star and target and apply these differences to both axes.) Then, leaving the RA dial in place, move the scope until the pointer matches the number on the RA dial that corresponds to whatever object you are looking for. Then line up the Dec. the same way and presto, you should see the object. If not, then you can use a technique called sky sweeping to, hopefully, find the object. Simply lock the Dec. and move back and forth in RA around the value you started with. If you don't see the object yet, unlock the Dec., increment it by about one-half degree, lock it again, and sweep in RA. Keep doing this until you find the object or move more than 5 degrees in both directions from the original Dec. setting. This method can be very quick, but it can also be very frustrating if you do not take the time to polar align reasonably well.
| Name | Constellation | Right Ascention | Declination | Visual Magnitude | When to View (Fall / Spring) | Distance | Sp.Type | Comment |
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| Name of Primary | Constellation | RA | Dec | Position Angle | Separation | Visual Mag. | Comment |
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| Name | Constellation | RA | Dec | Size (arcmin) | Distance | Comments |
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Age = 11Myr / 6Myr. |
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| Name | RA | Dec | Sp. Type | Distance | Visual Mag. | Planet Mass (Jupiter = 1) | Orbital Pd. | Comment |
|---|---|---|---|---|---|---|---|---|
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