When is polaris in transit

Place Polaris directly under the cross in the centre of the reticule see Figs. Rotate the mount one half turn about the RA axis. Polaris should remain under the cross in the centre of the reticule.

If it is necessary to adjust the position of the reticule, adjust the three small set screws on the Polar scope see Figs 3 and 4. Make very small adjustments by moving only two of the screws at a time.

Adjust the screws to move Polaris half the distance back to the centre of the reticule. This is because Polaris started in the centre of the reticule and by rotating the mount degrees, Polaris moved exactly twice the distance between the centre of the reticule and the centre of rotation. The centre of rotation lies midway between the centre of the reticule and the new position of Polaris.

Do not turn any of the set screws more than one-eighth turn at a time or the reticule will disengage from the set screws. Do not over-tighten these screws too much or the stress could fracture the reticule. Now re-centre Polaris under the cross in the middle of the reticule using the Azimuth and Altitude adjustments. Repeat the entire procedure until Polaris remains in the centre of the reticule when the mount is rotated about the RA axis.

With some practice, you should be able to align the reticule with the RA axis to within about 2 arc-minutes. Once this adjustment has been made successfully, it should not be necessary to carry out this procedure again. The Polar scope in combination with the RA setting circle constitutes a circular slide rule. After turning on your mount we should carefully insert all of the parameters it asks.

Location coordinates, time zone, date and time, daylight savings. After going through all of the setting we getting to the screen of Polaris's Hour Angle. But before we continue we need to know if this is accurate. In the days that I was writing this, it was known that SynScan software uses J Epoch static coordinates and Hour Angle reported by Handset was outdated.

For next years there probably would be some changes in softaware and it might use JNOW coordinates, but if you didn't updated and use old firmware, you should check this out.

To check out for how much my Handset was outdated I used 3 different software to verify the Hour Angle coordinates. Polaris by Gary Gawthrope. PolarisFinder v1. I have entered same location coordinates, date and time to each of the three programs and I got very similar results from all three of them and they were agreed that the HA was for that time.

So I had noted this and will keep it in mind when I'm next time in the field. Now, going back two steps, we going to use the reported by Handset Hour Angle position of Polaris and align our mount accordng to it. Now we release the RA clutch and turning the axis to align the hour scale with the HA we got from Handset.

If your handset is updated, or you have precise coordintes, you may use them now, but I had outdated Synscan and as you remember I had it 15 minutes rush. So instead of using I will use the corrected HA of as shown in the image. After that, we engage back RA clutch and now will bring the Polaris using Alt Az bolts of the mount to the small bubble of the Polar Finder. As I have mentioned before, I love to be precise. And after we engage the clutch and try to move our mount with the bolts, Polaris in the sky keep moving while our mount is stationary, which means, that if you fast, then it's ok, but if it takes you so time to bring the Poalris to the bubble, the Poalris have been already moved.

Now I can relax and accurately bring the Polaris to he's bubble without being worried for how long it would take me. Another thing to keep in mind. Probably all of our old Syntha Polar Finders are outdated. I shall be interested to see how long an exposure I can reasonably get using the polarscope rather than drift alignment. Post by Andrew INT » Thu Mar 19, am Hi Pete, Regarding your statement: "although Polaris was on the large circle, it had rotated about thirty degrees round from the small circle.

When you first align Polaris you would have rotated the axis so that Cassiopeia and Ursa Major were correctly positioned- then made adjustments to place Polaris in the small circle. Since the mount is not tracking, Polaris will begin to move around the larger circle.

However, the central cross will in fact remain fixed to the NCP. Remember that you are aligning to the NCP, and not Polaris. Kind regards, Andrew. Polaris transit time for the HEQ5 polarscope setup Post by weymouthpete » Thu Mar 19, pm Many thanks folks, it's really great to be able to get help so easily. All understood. The polarscope looked rather daunting at first but I feel much happier with it now.

I'm just hoping to avoid drift aligning every time. The polarscope doesn't have a correcting prism so what your seeing is wrong way up. If not ignore it at this point and carry on. Setting the date and time We now need to set a date and time for a known transit of Polaris.

For the sake of this tutorial and ease of visibility on the accompanying pictures we are going to set a transit time of on October 10th. To set date and time simply turn the Date Circle Fig 7 until the date you require is in line with the time you require for transit. The date circle is divided into months and days with markers for every 2 and 10 days. You can see in Fig 7 the Date Circle being turned to its setting for the transit time of on October 10th - i. The RA Index has two sets of numbers.

The upper numbers are for the Northern Hemisphere the lower numbers are for the Southern Hemisphere. How do you know what time and date to use as a transit?