NexStar 4SE Manual
Table Of Contents
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- Avertissement
- ( Procédure d'alignement
- ( Sky Align
- ( Alignement automatique sur deux étoiles (Auto 2-Star)
- ( Mise au point
- ( Calculer le grossissement
- ( Indices d’observation générale
- ( Conditions de visibilité
- ( Transparence
- ( Illumination du ciel
- Alimentation portable réf. C 479
- Plots de trépied anti-vibration réf. C 1174
- Annexe A – Caractéristiques techniques
- Annexe B – Branchement RS-232
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- Warning
- _
- Assembling the NexStar
- Hand Control Operation
- Improving Pointing Accuracy
- Object Catalog
- Direction Buttons
- Setup Procedures
- Camera –
- Identify
- Precise GoTo
- Scope Setup Features
- Utility Features
- Image Orientation
- _
- _
- _
- _
- _
- _
- _
- Focusing
- Calculating Magnification
- Determining Field of View
- General Observing Hints
- The Celestial Coordinate System
- Motion of the Stars
- Polar Alignment
- Observing the Moon
- Observing the Planets
- Observing the Sun
- Observing Deep Sky Objects
- Seeing Conditions
- Care and Cleaning of the Optics
- _
- _
- Appendix A - Technical Specifications
- _
- Appendix B - Glossary of Terms
- _
- _
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- 1235081856_4semanualspanis
Up to this point, this manual covered the assembly and basic operation of your NexStar telescope. However, to understand your telescope
more thoroughly , you need to know a little about the night sky. This section deals with observational astronomy in general and includes
information on the night sky and polar alignment.
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To help find objects in the sky, astronomers use a celestial coordinate system that is similar to our geographical coordinate system here on
Earth. The celestial coordinate system has poles, lines of longitude and latitude, and an equator. For the most part, these remain fixed
against the background stars.
The celestial equator runs 360 degrees around the Earth and separates the northern celestial hemisphere from the southern. Like the Earth's
equator, it bears a reading of zero degrees. On Earth this would be latitude. However, in the sky this is referred to as declination, or DEC for
short. Lines of declination are named for their angular distance above and below the celestial equator. The lines are broken down into
degrees, minutes of arc, and seconds of arc. Declination readings south of the equator carry a minus sign (-) in front of the coordinate and
those north of the celestial equator are either blank (i.e., no designation) or preceded by a plus sign (+).
The celestial equivalent of longitude is called Right Ascension, or R.A. for short. Like the Earth's lines of longitude, they run from pole to
pole and are evenly spaced 15 degrees apart. Although the longitude lines are separated by an angular distance, they are also a measure of
time. Each line of longitude is one hour apart from the next. Since the Earth rotates once every 24 hours, there are 24 lines total. As a result,
the R.A. coordinates are marked off in units of time. It begins with an arbitrary point in the constellation of Pisces designated as 0 hours, 0
minutes, 0 seconds. All other points are designated by how far (i.e., how long) they lag behind this coordinate after it passes overhead
moving toward the west.
Figure 6-1
The celestial sphere seen from the outside showing R.A. and DEC.
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