Operational Telescope : Celestron Nexstar 4 SE

In the previous post, we have discussed about the parts and functions of Celestron Nexstar 4 SE telescope, visit this link Celestron Nexstar 4SE  .In this post, we will discuss about the operational of this telescope. here are some guides:

Source : Manual Book Celestron Nexstar 4 SE

1. Assembling.
a. Set up a tripod and set the plain by using a waterpass.
b. Attach the mount and the telescope tube.
c. Attach the star pointer and calibrate it by adjusting altitude and azimuth knob, keeping the pointer pointing at the same point as the point on the telescope tube.
d. Install the energy. Energy can be obtained by installing 12v AC adapters or by using 8 AA batteries.
e. Attach the hand control

2. Positioning 
There are two positions that can be used to operate the telescope, depending on what method is used :
a. Alt-azimuth Method,
By this method, the operation of the telescope will correspond to the horizontal coordinates, the telescope will move horizontally and vertically. with this method the telescope must be arranged northward with the aid of the compass, then the telescope tube is set to the index position.
b. Equatorial Method
By this method, the operation of the telescope will correspond to the equatorial coordinate, the telescope will move to adjust the declination value and ascensio recta value of celestial body. with this method the latitude stick must be adjusted according to the observer's latitude, then the tube is set at the index position, and the position of the telescope must face to the meridian.

3. Operational 
a. Set Up the Controller 
There are some rules to set:
- Coordinates, can be input manually or through a city database
- Date
- Time, current time at the time of setting.

b. Alignment
- Sky Align, using this alignment we will be guided by the telescope. telescopes will choose the best celestial bodies to serve as alignment objects, can be stars, planets or other objects that are easy to detect.
- Auto Two-Star Align, using this alignment we will be selected 2 stars automatically to serve as alignment object.
- Two Star Alignment, we need to select manually 2 stars for the alignment object.
- One-Star Align, we need to choose one star for the alignment object.
- Solar System Align, we need to choose one object that include to solar system, that is planet or sun.
- EQ North / EQ South Alignment, this alignment is done when we choose to use equatorial method when doing step positioning. such as some alignment above, this alignment also has some kinds : EQ Auto Align, Two-Star Align EQ, One-Star Align EQ, EQ Solar System Align.

To improve calibration accuracy, choose alignment that supports a large number of sky objects (2 or more), if alignment is done but the accuracy level is bad, so alignment can be fixed with "sync" menu.

c. Tracking
After doing some arrangement as we mentioned above then telescope can be enabled to see the celestial objects automatically and follow it's movement. there are several objects that can be observed, including by using the following menu:
- LIST Menu, to search for sky objects "Named Star, Named Object, Double Stars, Variable Star"
- Catalog menu (M, CALD, NGC, STAR), to search for celestial objects through the number of objects.
- PLANET menu, to search for planetary celestial bodies.

Observation of celestial bodies can also use several methods such as:
- Tour Mode: to see interesting sky objects when observation time

- Constellation Tour: to see and observe the configuration of the stars that make up the constellations.

d. Focusing 
This stage is to be done to sharpen the image produced on the eyepiece lens, this stage is done by turning Focuser on OTA until our eyes feel comfortable to see the object, and the result object is not blur. Each observer's individual eye is different in focus settings, this is because of the possibility of eye defects in the eye's lens

e. Setup Tracking
Telescopes can follow the movement of celestial bodies, but it must be set in advance setup tracking with 2 settings:
- Tracking Mode, must adapt to the telescope mounting method. (Alt-Az, EQ North, EQ South)

- Tracking Rate, must adjust to the object being observed (Sideral, Lunar, Solar).

If yo want to compare the method of this telescope with other telescope visit this link. Opertional Telescope : Ioptron Minitower II.

The Pole of Earth and The Point of Compass

The Poles
Pole are defined as an axis, the polar division of the earth exists a variety, including the magnetic poles of the earth and the geographical poles of the earth:

The Poles of the Earth
Source : http://www.calendarinthesky.org

1. Earth's Magnetic Pole
Have you ever had a compass? the compass you have will show you the direction of North, East, South and West. This direction is a magnetic direction. The direction indicated by the compass is the result of the pulling force of the Earth's magnetic poles.
The Earth's magnetic pole is not right at the Earth's axis, the Earth's magnetic pole position is fluid, the North direction is indicated as a magnetic North that is affected by the gravitational pull force of the earth, so it has a different value every day, and every where.

2. Earth's Geography Pole
This pole is the original axis of the earth, its position remains at one point, and does not change. The polar position is at 90 degrees from the Equator (North Pole), and also -90 degrees from the Equator (South Pole). The rotation motion of the earth for approximately 24 hours rotates through this axis.

Inclination and Declination of The Compass
Source : http://digilander.libero.it

Compass is a tool that use the magnetic poles of the earth. Although the compass does not show the right direction, it can still be used accurately (leading to Earth's geographical poles) with some corrections, such as declination and inclination.
Magnetic declination is a horizontal shift toward the east or the west. Magnetic Inclination is a vertical shift toward the north or east direction of the compass. The value of this declination changes every day, we can check at Magnetic Declination. Meanwhile, the inclination value varies everywhere, depending on the position of the compass in the latitude. If the compass is in the southern latitudes, then the inclination of the compass will lean towards the south, and vice versa.

Points of The Compass

Points of The Compass
Source : https://en.wikipedia.org

Point of Compass is a guide to determine direction, usually used in Navigation system. There are 8 principle directions in this point of the compass system. Namely : North, Northeast, East, Southeast, South, Southwest, West, Northwest.
There are several ways to know the true winds, one of them is by using a compass as I mentioned above. Another way is to use the Sun :

1. Shortest shadow
Plug the stick to the ground in a flat position. With this method we are only looking for the shortest shadow when meridian pass/zawal (Sun at the zenith point), then we see the Sun declination value, if the declination of the Northern Sun is positive, so the shadow of the Sun points south direction, if the declination is South or the value is negative, so the shadow of the Sun leads North direction. But this method has a weakness, if the Sun is right above where we are, so there will be no shadow.

2. Shadows before and after Merpass / zawal
Plug the stick to the ground in a flat position, then make 1 to 3 circles around the stick with the stick as the center point. Observe before merpass, and observe the shadow that the end of the line touching the circle lines you have created. And make a point on the tangent. Observe after merpass, and observe the shadow that the end of the line touching the circle lines you have created. And make a point on the allusion. Connect the 2 points. The first point shows the true West direction, the second point shows of the true East direction.

3. Use the azimutal value of the Sun
This method is practically easier, but this method uses calculations. the first way is Shooting the Sun, then Counting the azimut of the Sun and then pointing towards 0 value (True North).

The above ways will be explained in another article.

Crescent Image Results : Dzulhijjah 1438.

The observation of Crescent on Dzulhijjah in Indonesia was done on August 22, 2017. at that time I obseved in Condrodipo Hill, Gresik, Indonesia. This place is a very special, why is it like that? because in this place there are often reports that the crescent is seen, although in other places not seen. It is also happening on the Crescent observation at Dzulhijjah 1438 yesterday. Hilal was successfully viewed by 5 people. 5 people are not including me, because I have never seen a Crescent before. Indeed, I feel seeing the Crescent vaguely, but I am not sure about it. so I decided to believe that I did not see.

Crescent Capture

5 successful observations in the condrodipo were performed with the naked eye, observations using cameras, telescopes, binoculars and theodolites failed to occur. I am confused with it. why so, theoretically it is impossible to happen, the limited view of the eye can overpower by the view of very sophisticated optical devices.

Before going home, I tried to ask for the image from the camera that connected to the telescope and I got 38 photos of the recording result when the hilal observation. The photoa are taken with the same settings, JPEG format, ISO 1600, Exposure 1/5" and f/3.5.

Cresent Observation Image at 17:46 UTC +7 

Cresent Observation Image at 17:50 UTC +7

I spent days trying to observe by enlarging the photographs, observing point by point, line by line, angular by angle but no results.

Then I have the initiative to edit the photo in photoshop. I set its contrast, its black and white, its exposure and I succeed to do it.

Below, the results of the edited image:

 Edited Image at 17:46 UTC +7

Pointing Crescent Image Result at 17:46 UTC+7

The Crescent Image Result at 17:46 UTC +7

Edited Image at 17:50 UTC +7

Pointing Crescent Image Result at 17:46 UTC+7

The Crescent Image Result at 17:50 UTC +7

Of these results there are still irregularities, why the position of the Crescent at 17:50 higher than at 17:46? My hypothesis, this happens because the telescope setting is still using Sun Speedrate, not using Lunar Speedrate.

The Crescent above is very difficult to see and edit, because several factors of the wrong arrangement. in the photo is not supposed to wear high ISO, it is better to use low ISO with long Exposure. And the format of the image is also better using the RAW format for easy editing and searching, not the JPEG format.

Operational Telescope : Ioptron Versa 108 ED APO OTA with Ioptron Minitower II-8300-2G Mount

A. The Parts

The Parts of OTA

1. Telescope Tubes

2. Objective Lenses
3. Lens Fence
4. Tube Clamps
5. Clamp Key
6. Focuser Hinges Key
7. Eyepiece Placement Hole
8. Focuser
9. Eyepiece Key
10. Focuser Key

The Part of Mount

1. Clamp Lock
2. Telescope Tube Clamps
3. Mount Hinges
4. Azimut / Horizontal Key
5. Screw Regulator of the Square
6. Southern Sign
7. Waterpass
8. Vertical Hinge Key
9. Balancing Counter Key
10. Iron Measuring Equilibrium
11. Load Balancer

The Button of Controller

B. Specifications
1. OTA (Optical Tube Assembly)
Aperture: 108mm
Focal Length: 648mm
Ratio: F6
Lens Type: 2 elements Air-spaced ED S-FPL51 + S-NBM51 glass
Focuser: 2 ", 360 ° Rotatable 1:11 Crayford dual speed focuser
Tube Length: 535 mm (Fully Retractable)
Tube Weight: 12 lbs.

2. Mount
Mount: AltAzimuth Mount, Equatorial mount with special tripod
Body Materials: Aluminum
Motor: Dual-Axis DC Servomotor, DC12V
Speed: Dual-Axis, 9-Gear, Electronic (1 × 2 ×, 8 ×, 16 ×, 64 ×, 128 ×, 256 ×, 512 ×, MAX)
GPS: 32-channel GPS
GOTO System: GOTONOVATM 130,000 objects database
GOTO accuracy: 1 Arc Min. (Typical)
Tracking: Automatic
Battery: AA x 8 (Not Included)
Power Requirement: DC 12V ± 2V,> 1.2A
USB Port: Yes
Protocol : ASCOM
Firmware Upgrade: Yes
Computer Control: Yes

C. Usage

1. Installation (assemblying)
Installation of the device consists of a tripod, mount, telescope, ballast, hand controller, and others so that all installed properly and ready to operate.
One of the most important things in this step is balancing between the telescope with the balancer. The unbalanced state will affect the accuracy when tracking.
In addition, leveling (flattening position) of the tripod should also be considered, using the waterpas or (bubble level indicator) found on the bottom of the mount.

2. Initial Position Settings
Positioning the telescope on home position (parking position) or initial condition correctly. For the Ioptron MiniTower II telescope with Altazimuth Mode, the home position is facing the mount to the South and the OTA position is raised to the zenith. At this positioning stage the compass is required to show the exact South direction.

3. Operational
A. Set Up Controller
There are some important settings that need to be set:
1. Time
2. Time Zone
3. Coordinate Place
4. Mount type

B. Alignment
Although telescope already directed to the South and Zenith, but adjustments to the state of the sky (calibration) still needs to be done, because not necessarily our telescope is pointed to the South and Zenith appropriately.
There are several calibrations that can be done:
1. One Star Alignment
2. Two Star Alignmnet
3. Three Star Alignment
4. Polaris Position Alignment
The suggested calibration is calibration with 3 stars or with Polaris, but for locations with southern latitudes, Polaris calibration can not be used, because Polaris stars can not be observed in the southern latitudes.
Calibration of 3 stars can only be used at nighttime, in the daytime no stars can be observed cause the stars beaten by the sun, so for daytime observation, or Crescent observation for "rukyatul hilal", can be done  Sun Position calibration .
The calibration of the Sun position is not in the "One Star Alignment" menu, so we use another method, "Slew and Sync" menu, we navigate to the Sun in the "Select and Slew" option, then we sync the Sun's observations on the telescope lens with the "Sync to Target" option.

C. Tracking
After the data is loaded, and calibration is done, we can select the object to be observed by selecting "Select and Slew" menu. This menu provides various objects that can be observed. There are about 13,000 objects in this mount database. By pressing "enter" the tracking process can automatically be done.

Display on the Controller

D. Focusing

This stage is to be done to sharpen the image produced on the eyepiece lens, this stage is done by turning Focuser on OTA until our eyes feel comfortable to see the object, and the result object is not blur. Each observer's individual eye is different in focus settings, this is because of the possibility of eye defects in the eye's lens
.
E. Setup Tracking
The next stage is to set tracking speed, there are several options:
1. Sidereal Speed ​​/ Celestial Speed, observations for the stars
2. Solar Speed, Observations for the Sun and the Planet

3. Lunar Speed, Observation for the Moon / Crescent

Calculation of Qibla Direction for Indonesian Places

Indonesian Map's

Indonesia is located on the east of the Ka'ba, and is in the south of the Ka'ba, so in logical direction, the direction of the qibla in Indonesia leads to the North West. there are some data that must be searched first to calculate the direction of qibla, that is:

1. Latitude of Ka'ba (φk)
2. Longitude of Ka'ba (λx)
3. Latitude Place (φx)
4. Longitude Place (λx)

For Latitude and Longitude data Ka'ba is usually constant / fixed, but some people vary in its determination, one of the Ka'ba coordinate value ​​used is 21˚ 25 ' 21,01" N and 39˚ 49' 34,33" E. For coordinate data for the place can be searched with various tools, such as GPS. visit this link. Determine Coordinate with GPS.

This calculation uses the assumption that the Earth is a sphere, so this way using the Spherical Algorithm theory. The steps must be taken as follows:

1. Finding the longitude difference (λd) with the formula : λd = (λx - λx).
2. Finding the qibla direction angle (QD) with the formula: Cotan QD = Tan φk * Cos φx / Sin λd - Sin φx / Tan λd.
3. Then finding qibla azimuth value (QA) with the formula: QA = 360 - QD

Average Qibla Azimuth of Indonesia

The direction of the Qiblah that we count, measured from the True North clockwise to the value of the azimuth angle. For the example calculations will be discussed at the next session.

The Change of Qibla Direction 2

In the previous article, has been described how the potential for changes qibla direction at someplace that caused by the earthquake. Visit this Link! The Change of Qibla Direction.

Now, in this article we will describe one example of the shift of coordinates that caused by the earthquake, and the changing direction of qibla. How big is it? And how big is the change?

Simulation of The Change of Qibla Direction

One of the mosques we have sampled is the Baiturrahim mosque in Ule Lheue, Aceh, Indonesia. One of the areas that was hit by the Tsunami on December 26, 2004 with a strength 9.3 Mw. The tsunami was the result of an earthquake in the Indian Ocean, which took victims from six countries : Indonesia, India, Sri Lanka, Thailand, the Maldives and Somalia.

Simulation of Tsunami 2004 in Indian Ocean
Source : Wikipedia.com

Please see some image below, these images we got from Google satellite imagery in Google Earth App, in a few different times.

Image 1 : The Capture of Baiturrahim 2004

Image 1: Satellite images taken on June 23, 2004, before the earthquake occured. in this figure there is the coordinate value of the roof of the Baiturrahim Mosque is 5˚ 33 '21.4 "N and 95˚ 17' 1.7" E.

Image 2 : The Capture of Baiturrahim 2005

Image 2 : Satellite images on January 28, 2005, images taken several months after the earthquake. the coordinates shifted to 5˚ 33 '20.67 "N and 95˚ 17' 1.61" E. coordinates shifted to the South West.

Image 3 : The Capture of Baiturrahim 2009

Image 3: Satellite image on June 16, 2009, image taken 4 years after the earthquake. The coordinates again shifted towards the North East, the coordinates are 5˚ 33 '20.97 "N and 95˚ 17' 2.22" E

Image 4 : The Capture of Baiturrahim 2010

Image 4: Satellite images on July 8, 2010, shifting South East to 5˚ 33 '20.9 "N and 95˚ 17' 2.39" E

Image 5 : The Capture of Baiturrahim 2017

Image 5 : The last image on January 29, 2017, shifting North East to 5˚ 33 '20.95 "N and 95˚ 17' 2.54" E

Latitude Shift's

Longitude Shift's

Of the drawings, the greatest shift occurred between June 23, 2004 and January 28, 2005. where between the dates there was a very large earthquake. The latitude shifts by 0.73 " to the South and longitude shifts by 0.09" to the West.

There was also a substantial shift, between January 28, 2005 and June 16, 2009, after I searched further, there was also some earthquake that occurred between that date, at Nias, Indonesia in 2005 and at West Sumatra, Indonesia in 2007. The latitude shift by 0.3 " to the North and longitude shifts by 0.61" to the East.

For the other date the shift is not too large, is between 0.05 "- 0.17", because there is no earthquake, the shift according to our, occurs caused by the shift of the earth's plate, but not too large, so it didn't cause an earthquake.

As for the qibla shift, I have calculated the direction of the qibla from some conditions with spherical algorithms calculation, can be seen from the following table:

Qibla Direction Shift's

The shifting direction of the qiblah that happened was very small, and almost no effect, less than 0.5". The 0.5" impact was caused by the tsunami that occurred on December 26, 2004. Then the impact of the Nias and West Sumatra earthquakes was less than 0.3", while in other condition, the qibla direction shifted less than 0.2" .

A shift in the direction of qibla is very possible, although the shift is very small, but it should be checked regularly, because if the slight shift is repeated several times it will produce a big shift.

Visit this link for the previous discussion. The Change of Qibla Direction 1

The Change of Qibla Direction

Is it possible to change the direction of qibla ? may be. the direction of qibla still facing the Ka'ba in Mecca, but the direction that will shift. qibla direction may occur, this is caused by a shift in the earth's plate, or earthquake.

Source : www.emaze.com

In a study conducted by Yusfania, she explained about the shift location caused by the earthquake that occurred in Sumatra or the Indian Ocean, the study resulted in the conclusion that the earthquake that occurred in the Indian Ocean in April 2012 led to a position shift of 0.3 - 2.4 meters to North East.

This is a fact that we must accept, because if the position of a place changes, it will certainly change the coordinates of the place, and then it will have an impact on the shift in direction of the qiblah at someplace.

Earthquakes are very common, especially in Indonesia. Indonesia is a country with earthquake potential. This happens because the location of Indonesia which is the meeting center of the plates of the Earth, among others, Eurasia, the Philippines, Caroline, Indo-Australia, Pacific and several other minor plates (Hamilton: 1979). In addition, this earthquake is caused by tectonic activity of the plates. Plates it continues to move like the Eurasian and Indo-Australian plates which have an average moving northward, while the Philippine plate movements tend towards the northwest (Hamilton: 1979 in USGS: 2011). Associated with the philipine plate, the Caroline plate has a movement towards the southeast in part of Aru riverbed and towards the northwest in part of Yap riverbed (Seno: 1992 in USGS: 2011).

Therefore, in order to minimize the change of direction of the qibla at someplace, the direction of the qibla should be updated regularly. Because if the shift is collected caused by several earthquakes, then surely the impact will be great.

Renewal of the direction of the qibla should be done by experts, Islamic Astronomer, The Jurist and also Geodesy master. Intensive research should be made to the direction of the qibla at someplace that should also involve the community. So that the public knows about the facts of shifting the direction of qibla caused by a shift of the earth's plate, and for the public to be more careful.

Visit this link for the next discussion. The Change of Qibla Direction 2

Advantages and Disadvantages of Handheld GPS

Advantages and Disadvantages of Handheld GPS

Actually there are many types of GPS, not just handheld / portable GPS, but also GPS Navigation and GPS Smartphone. For the first of these I will discuss in advance about the GPS handheld, and now I will explain the advantages and disadvantages of GPS handheld.

Handheld GPS

GPS handhelds have a high sensitivity in receiving GPS signals and some devices are capable of receiving dual satellite systems from GPS and Glonass. We can also determine the height of place and direction in an area with satellit signal, there are also various additional sensors, for example barometric altimeter and electronic compass so that the determination of height and direction can be done without using satellite signal. This is usually an option in the settings.

The use of barometric altimeter sensors usually must first be done altitude calibration somewhere. We can also use this barometric altimeter to plot air or ambient pressure from time to time, which can help to observe changes in weather conditions.

The advantage of this GPS compass is that it is not influenced by the magnetic field and can guide the direction accurately as it is guided by signals from the satellites (not the buit-in compass sensor). This tool is certainly very helpful when measuring the direction of Qibla.

The area is remote with no phone signal and does not have internet. We recommend choosing a handheld GPS device. Maps are already stored inside, though the images are very standard, such as the appearance of road maps and soil contours, the data maps in the handheld GPS more complete, but usually sold separately (for each country) and the price is quite expensive. Maps do not need to be installed or downloaded. Because portable GPS has been installed one country map when marketed.

GPS handheld is better, more durable, waterproof and suitable for outdoor activities. Users need not be afraid of the natural conditions, because handheld GPS devices or portable GPS are designed for nature activities. Using this GPS we can find the way when through high-sensitivity wilderness, which acquires satellite signals quickly and tracks locations in challenging conditions such as trees and cliffs.

The battery can be replaced because it uses AAA batteries. One portable GPS device can last up to 25 hours. Very suitable for adventure activities in areas far from electrical energy.

But the obstacle, GPS handheld in terms of price is still quite expensive, for a GPS device ranges between Rp. 2,000,000.00 to Rp.10.000.000,00 or about $ 150 USD to $ 750 USD.

The disadvantages of all GPS, including GPS handhelds are GPS will greatly affect the geographical conditions of where we are. GPS will work well if where we are still has a wide sky. The following will be described wherever the GPS will experience a weakness in its use:

1.When someone is in the forest. With the conditions of the trees are so much then the signals that can be received will be a little maybe even no depending on the width of the forest.
2.When someone is in the water or when someone is diving. Do not expect to use this tool when diving.
3. Electronic devices that can emit electromagnetic waves may affect performance degradation rather than GPS.
4. Buildings. Not only when inside the building, being between 2 tall buildings will also cause an effect like being in a valley.
5. Signals that bounce, eg when in between high-rise buildings, can disrupt the calculation of navigation tools so that navigation tools can indicate the wrong position or not accurate.
6. Glass film car, especially metal-containing.

Menus and Functions on GPS : Garmin 76 C/CSX

I will explain about some menus or functions on the GPS. This time I use GPS Garmin 76 C/CSX. Some GPS devices also have a similar functions.

GPS Garmin 76 C / 76 CSX

1. Key Functions

Inside GPS 76 C there are several buttons that work include to:
A. Power button: Turns the unit on or off. If this button is pressed and released, it can work to adjust the backlight.
B. Zoom In / Out button: To set the size of the scale.
C. Find Button: To go to find menu page and display mob.
D. Quit button: To cancel data entry or close the page.
E. Page or Compass button: To go to the main page and turn the electronic compass off.
F. Menu Button: To enter options, confirm messages or data on-screen. This button can also be used for marking Sign and Waypoint.
G. Rocker Keys: To start moving lists, highlight fields, on-screen buttons, icons, enter data or move to the map section.

2. Getting Satellite Data

For the process of revenue data from satellite, then we must pay attention to the place and condition around. It is advisable to use the GPS in the open and have a wide view. The weather conditions must also be in good condition. For the steps are:
A. Turn on the GPS by pressing the power button. If the GPS has been turned on then it will say "Welcome". The page will quickly face the satellite page.
B. Observe the satellite page and GPS status message when it appears at the top of the page, and soon it will look like a GPSmap. This indicates it will start to search for satellite exploitation status. Not long after that will automatically show our position (latitude and longitude). Visit Determine Coordinate of Place with GPS for more info.

3. Selecting a Page

For all required information or data can be found in four main pages (display screen). These pages include satellites, maps, pointers, and menus. The trick is to press the page button to find the pages.
A. Satellite page: provides a reference for tracked satellites.
B. Page trip computer: provides data and information related to the science of shipping.
C. Page map: provides a view of a map and reference our navigation movement.
D. Page compass: provides guidance for a purpose and direction.
E. Page altimeter: provides path and pressure elevation.
F. Main menu: an existing directory in GPS to specify other settings.

4. Define Waypoint

Waypoint is a marking of places obtained by satellites in a GPS. To mark a place, we can access in the Find Menu by:
A. Press the page button and select the menu page. Press the Up or Down button and select the "Mark" section.
B. Press the enter key. The mark waypoint page will appear with the word "OK?", Hit enter. Waypoint has been stored in GPS memory.

5. Go to the Waypoint Menu
To enter the waypoint we have marked, then we use the Go To facility. How to use it is:
A. Press the page button and select the menu page. Press Up or Down button and select "waypoint". Press Enter. The waypoint page will appear.
B. Press the Up or Down button and select the tab that contains the desired waypoint name and press Enter. The existing waypoint review page will appear.
C. Press Up or Down button to select "GoTo" and press Enter.

6. Exploration on a Waypoint
In the use of the "Go to" facility, we will be directed to follow the directions on the waypoint. The directions provided are N, S, E, W (North, South, East, West). If we cancel, we can use the compass pointing stick to divert the direction toward us. The steps are:
A. Press the page button repeatedly until the compass page is shown. This page contains a bookmark that marks the direction to go.
B. Press the quit button to move to the map page and watch our progress toward the waypoint. The pointer line will show the map and the position arrow movement as we move it.
C. Press the quit button again to move to the travel page. This page provides travel data such as a travel odometer, maximum speed, and more.
D. To stop navigation, press Menu then select stop navigation and then press Enter.

7. Cleaning Track Log
If we have used GPS for multiple trips, then the map view will be full because storing tracks or paths that we have been through. To use this facility the way is:
A. Press the page button and select the menu page.
B. Press Up or Down button and select "Tracks".
C. Press Enter. Use the Up button and select "Clear". Press Enter.

8. Using Map Page 
To use the map page can be done by:
A. Press the page button to go to the main page to the map page.
B. Press the menu button to navigate to the map page selection.
C. Start moving and observing the position arrow on the top of the map. Use the Rocker button to move and move highlights a map item or look into other map areas.

Determine The Coordinates of a Place with GPS.

In the calculation of Islamic Astronomy, the thing that is always required is the coordinates of a place. Many ways and tools can be used to know these coordinates. One of the most famous ways is using GPS (Global Positioning System)

GPS is a navigation and positioning radio system that utilizes satellites as a means of communication. This tool is usually used in vehicle navigation, be it land, sea or air vehicle. Ship and aircraft communication with the station is needed, in order to avoid accidents. GPS is used to know each ship or aircraft position, then reported to the tower / station supervisor at the nearest port or airport.

This GPS will monitor signals from satellites, then GPS will accept the position of the place be it latitude, longitude or altitude place on Earth.

In the Islamic Astronomy, GPS that easy to use is a type of handheld GPS that can be taken anywhere.

GPS has a different level of accuracy, depending on the brand and type of GPS. but overall the tool is quite accurate in determining the coordinates of a place or area.

In this explanation, I will practice using GPS Garmin 72H, but overall, various GPS has a similar way to operate GPS for coordinate determination. The way is :

1. Turn on the GPS in the field, not in the room, around tall buildings, tunnels, and dense forests.

2. Wait a while, about 1-3 minutes, so that GPS receives satellite to make configuration latitude, longitude and altitude data complete.

3. The minimum number of satellites captured to generate coordinates is 4 satellites. And wait a while until the "Location" or "Accuracy" sign shows the smallest number. That sign is the maximum error of the GPS point being, which is predicted by GPS satellite.

4. Then record the coordinates that appear.

Garmin GPS 72H
Souce : https://www.amazon.com

Example image above, the resulting coordinates are 38 degrees 51,498 minutes North Latitude (N) and 94 degrees 47.838 minutes West Longitude (W).

5. if you want to know the height of the place, press the "page" several times until entering on the page high information place.

Good luck!

Islamic Astronomy Tools : Celestron Nexstar 4 SE

In studying a science, of course there are theories and also field practice, studying physics and biology must definitely practice in the laboratory, learning sports science should definitely practice in the field, learning the language of science should also practice in the language laboratory.

The need for practice in learning a science is a necessity, as well as the science of Islamic Astronomy. according to some people's understanding, Islamic Astronomy deals with the calculations of heavenly bodies, but they are useless if they are not applied in the field. there are several tools that become the needs of the astronomers, one of which is the telescope. In Islamic Astronomy the telescope is usually used for rukyatul hilal (observing the crescent) in the determination of lunar calendar, or for eclipse observation.

Source : https://www.celestron.com

This time I will discuss a bit about the use and specifications of Celestron Nexstar 4 SE telescope.

CELESTRON NEXSTAR 4 SE

The telescope has two functions, the first of which serves as a horizontal telescope, and the second serves as an equatorial telescope. This is one of the advantages of this telescope. for the tube type is a reflector telescope with a cassegrain telescope design.

Telescope parts:

Source : https://www.celestron.com

1. Optical Tube, the main part of the telescope, in this section will occur light reflection, which will then produce images of distant objects.

2. Star Pointer Finderscope, this section serves to make it easier when shooting sky objects.

3. Eyepiece, this part is the ocular lens of the telescope, this lens can also be changed to adjust the magnification of the telescope.

4. Focuser Knob, this section is used to adjust the focus of the telescope image. This section should always be arranged, especially if we replace eyepiece or change of observer, so that picture is always sharp.

5. Threaded Photographic Adapter, an adapter for SLR / DSLR cameras that have been connected by T-ring

6. Flip Mirror Control, Flip Glass used for image selection, whether light is forwarded to the camera ?, or is reflected to eyepiece ?.

7. Battery Compartment, Battery Place, this telescope needs 8 batteries to run it.

8. Tripod, this part is the foot of the telescope that supports mounting and tubes. This section is also commonly used to regulate the flatness of the telescope.

9. Accessory Tray, place to put various accessory, like eyepiece, T-ring. On the side of the Accessory Tray there is a vertical stick, this stick is used to support when we will use the telescope with equatorial model.

Source : https://www.celestron.com

10. ON / OFF Switch, the button to turn the telescope on and off, beside this button is also an AC Adapter input which is used to run telescope without battery.

11. Hand Control, this part is a remote used to control the telescope.

12. Liquid Crystal Display, Screen on the remote, inside is also usually listed coordinates of the telescope and also objects observed celestial objects.

For how to use? please visit this link Operational Celestron NexStar 4SE.

ISS Satellite

You must know satellite already? A satellite is an orbiting object on a celestial body, including the Earth. There are two kinds of satellites, natural satellites and artificial satellites. Earth has a natural satellite, one of its functions on Earth is a marker of time for Muslims. While artificial satellites quite a lot, its function is diverse, such as as a means of communication, as weather research, means of transmission of military equipment, and others. More details refer to the following description:

Astronomy Satellite
Used to study planets, stars, and other objects. One example is the Hubble satellite used to photograph the Red Rose Nebula.

Communications Satellite
It is functional for telecommunication, radio, and television purposes using microwave frequencies.

Earth Monitor Satellite (GPS)
Used for navigation and map creation. Radio age conditions that let users know their exact position through the GPS system.

Weather Satellite
Serves to record and submit information about the weather and climate conditions of the Earth. It is a "building" that allows people to live in outer space. This station has been specially designed, so it can be inhabited for several months or even years.

Military Satellite
Is a telegraph satellite or an Earth monitor used for military purposes.

Small Satellites
Small super satellites are flown in space. For example mini-satellites (500-2000kg), micro satellite (10-200kg) and nano satellites (below 10kg).
To be able to operate satellites launched into orbit with the help of rockets. Developed countries such as the United States, Russia, France and Lately China, already have stations to catapult satellites into orbit.

Source : http://www.infoastronomy.org

ISS (International Space Station) is one of the first satellite launched on November 20, 1998. The launch of ISS is a project of 13 countries, which is used for various functions such as research of various disciplines, Biography, Biotech Geography, Geodesy, Physics, Astronomy, Space Science and others.

ISS has another name "Zarya", designed with a very large size, ISS becomes the largest satellite when compared with other satellites. And has many rooms, including 5 bedrooms, 2 bathrooms and 1 gym, there are also several laboratories specifically designed for research. Many astronauts from various countries who have successfully stop off this ISS satellite, spend many days even for months there, carry out research tasks.

Inside ISS
Source : http://schools-wikipedia.org

Inside ISS
Source : http://schools-wikipedia.org

Inside ISS
Source : http://schools-wikipedia.org

ISS when viewed from the earth has a special and interesting position when compared to other satellites, the ISS can be seen from Earth, because of its large size and has a low orbit about 380 km from Earth, so the orbit of ISS is almost round.

Have you ever been watching the sky, then seeing bright spots like a walking star? Is it a meteor? Is that a plane? It turns out not both, but one of the largest human-made satellites, the International Space Station (ISS).

At certain times, the ISS will be visible in the night sky of your area. ISS will look like a bright star that moves fast over the horizon. ISS is so bright, it can even be seen from downtown though.

Capture ISS with Long Exposure
Source : https://www.universetoday.com

Ever seen ISS? please try it! You can register directly to this Link to get a notification when ISS will pass the sky where you are. Or you can detect through simulation software like stellarium.

Good luck!

Prayer Times Marker

Source : http://www.algonaefree.org

One of the valid conditions of prayer/salat is in time. The times of prayer have been arranged in the Qur'an and Hadith, namely in Surat al-Isra ': 78:

أقم الصلاة لدلوك الشمس إلى غسق الليل وقرءان الفجر إن قرءان الفجر كان مشهودا

Meaning:
Establish prayer from after the sun slip until dark of night and time of the Qur'anal Fajri. The Qur'anal Fajri is actually witnessed (Surat al-Isra`: 78)

According to the commentators, in this verse is mentioned the time of prayer that is after the sun slipped, the prayers of Dhuhur and Asr. While the dark night is the prayer of Maghrib and Isha` and Qur`anal Fajri is the prayer of Shubuh .

Whereas if you want to more specifically know the theorem about the times of prayer, we can refer to the hadith of Rasululah that saheeh and qath`i. Among these are the following hadith, which means:

From Jabir bin Abdullah ra. That the Prophet was approached by Gabriel and said to him, "Rise up and do the prayer." So he did the Dhuhur prayer when the sun slipped. Then as Asr approaches and Gabriel says, "Wake up and do the prayer." So he did the Asr prayer when the length of the shadow of all things equal to the length of the object. Then the time of Maghrib approaches and Gabriel says, "Wake up and do the prayer." So he performed the Maghrib prayer when the sun sets. Then Isha time comes and Gabriel says, "Wake up and do the prayer." Then he SAW perform the Isha' prayer when syafaq (red clouds) disappears. Then when Shubuh comes and Gabriel says, "Wake up and do the prayer." So he did the Shubuh prayer when dawn broke. (Ahmad, Nasai and Tirmizy.)

1. Fajr Prayer Time (Shubuh)

Starting from the appearance of "Fajr Shadiq/True Dawn" until the rising of the sun. The dawn in Arabic is not the sun. So when mentioned dawn, it is not sunrise. Dawn is a rather bright white light that spreads on the eastern horizon that comes just before sunrise.

There are two kinds of dawn, namely "Fajr Kazib/ False Dawn" and "Fajar Shadiq/ True Dawn". "Fajr Kazib" is the dawn that "lying" as the name implies. That is, in the early hours of the morning, there is a light that extends and leads up in the middle of the sky. Shaped like a wolf's tail, then the sky becomes dark again. That is "Fajr Kazib".

While the second dawn is "Fajr Shadiq", which is the dawn of a really dawn which is a rather bright white light that spreads on the eastern horizon that appears shortly before sunrise. This dawn marks the entry of the Shubuh time.

Simulation of Shubuh Time

While the end of the Shubuh time is the rising of the Sun.

In the science of astronomy, the position of the Sun is usually denoted in an altitude value. For the beginning of dawn itself varies, some are wearing a sun-height value of -20 degrees to -15 degrees below the horizon.

Difference of Shubuh Height Value

2. Dhuhur Prayer Time

Starting from the sun is just above the head but has started to slightly leaning towards the west. The term often used is the slipping of the sun. As free translation of the word "Zawalus Syamsi". But this term is often confusing because if it says that the "sun is slipping", some people will wrinkle his forehead, "What is the slipping of the sun?".

"Zawalus Syamsi" is the time at which the position of the sun is above our heads, but a little has begun to move westward. So not right above the head. Or in Arabic terms also known as Istiwa'.

Simulation of Dhuhur Time

The end of the prayer time of Dhuhur is when entering the time of the Asr prayer.

The value of the sun's height at the time of entry Dhuhur prayer is approaching 90 degrees.

3. Asr Prayer Time

There are some differences in starting this Asr prayer :

First opinion, Asr prayer begins when the shadow of an object is equal to the height of the object plus the shadow of the object when time Dhuhur. The value of the sun's height at this position is less than 45 degrees.

Second opinion, Asr prayer starts when the shadow of an object is equal to 2x height of the object plus the shadow of the object when time Dhuhur. The value of the sun's height at this position is about 26 degrees 34 minutes

Simulation of Asr Time

The third opinion of Asr prayer is Wustha prayer is the prayer performed in the middle between Dhuhr and Maghrib prayer. The value of the sun's height at this position is more or equal to 45 degrees

But the most famous opinion is the first opinion.

4. Maghrib Prayer Time

Starting from the setting of the sun and this has become the ijma` (agreement) of the scholars. That is since the loss of all the solar spheres in the swallow of the earth. And ended up entering the time Isha'.

Simulation of Maghrib Time

The value of the sun's height at the time of Maghrib prayer is approximately -1 degrees.

5. Isha' Prayer Time

Isha' prayer begins when the emergence of red clouds in the sky.
The value of the height of the sun is also different, there is a opinion that the height of the Sun during Isha' is -18 to -15 degrees below horizon.

Simulation of Shubuh Time

And the end of the Isha' prayer is when entering the time of Shubuh prayer.

Difference of Isha Height Value