The 29th Astronomical Camping
For Crescent Observation

Last Updated 17 September 1999

Observing at Night

JAS held the 29th astronomical camp in Al-Shoubak Mountains at the night of 09-10 September 1999 to observe the crescent of Jumada Ath-Thani. We were aware that seeing this crescent from Jordan won't be easy, and so we must be in a good preparation for it.

Recently JAS has been granted a computerized telescope, 10-inch Meade LX200. Which points at any given coordinates !! So we managed to use it to point at the crescent instead searching for it !

Another important factor is the clearness of the western horizon. JAS has paid a great attention for this point, and so we have been searching for good area to observe the crescent from. This area must be high-elevated, and with clear and unobscured western horizon, and needless to say that this area must be easily reached by the observers !! All these factors were meet in an area in south Jordan ! Which is Al-Sharah Mountains, specifically Al-Shoubak Mountains. We have visited this area twice before this observation, and we found it one of the best locations to observe from. It is about 220 Km south of Amman, and our location was at 1646 meters above sea level ! Which is good.

Back to the telescope ! It is right that the telescope can point at any desired object or coordinates, but it must be aligned before that ! The alignment can be made by pointing the telescope at two known stars, and then the computer will will work. That means, the motor drive and the pointing function will work ONLY after the alignment ! This was the BIGGEST problem we faced !! The crescent will set after about 30-40 minutes of the sunset ! And we need to search for the crescent immediately after the sunset ! That means we won't find stars at that time to do the alignment ! And this is the reason for going a day before to the observing location ! We will do the alignment at night, and will leave the telescope working until the sunset ! The location itself was very suitable for observation. We can definitely say that limiting magnitude at night was more than 6.

Well, we traveled from Amman on 9 September and reached the location after about 30 minutes of the sunset, we mounted the telescope, and did the alignment. We spent the night observing the Messier Objects. We saw more than 80 of which, and we observed the Sun, Venus, Mars, Jupiter, Saturn, and the Moon (later on) :-) !

At daytime, we traveled among the great mountains at that area !!! It is a magnificent area ! We traveled to a mountain which is 1733 meters above the sea level (Which is the highest mountain in that area, and the third highest one in Jordan). It was just one Km behind us, and initially the observation had to be done there, but we couldn't for a temporal reason. As for the western horizon !! We definitely can say that it was the most beautiful horizon we have ever seen ! The clouds were below some lower western mountains, and the western horizon seemed to be cloudy ! But it was the 'real' horizon (This can be seen in one of the below photos). We could easily see the Earth's Shadow in the western horizon at the sunrise ! It was a great show ! It was as a huge arc at the western horizon, and kept decreasing until the sunrise, where it was then as a very thin line above the horizon.

At daytime we kept seeing Venus and some bright stars, and before about two hours of the sunset of 10 September, I noticed that the clock of the telescope is ahead by two minutes, so I fixed it. BUT, by doing so I have confused the computer of the telescope and the alignment was damaged !!! Oh my God ! We have spent more than 22 hours in the mountains and slept in the bus there to do the alignment, then it is damaged at the last two hours !!! What a feeling !!! :-). However, we spent about 30 minutes trying to solve this problem, and thank God we did ! Surprisingly, we were able to do two-star alignment at daytime !! We used Vega and Arcturus ! After that the telescope worked correctly.

The coordinates of the location are:-

- Longitude: 35:30 E
- Latitude: 30:24 N
- Elevation: 1646 m
- Time Zone: +3:00

The observing team was:-

• Marwan Shweiki (Vice-President of JAS).
• Mohammad Odeh (Head of ICOP).
• Mohammad Alawneh (Member of ICOP).
• Tarek Katbeh (Member of ICOP).

Well, now is the sunset !!! The Sun had to set at 18:51 local time from the sea level, but as we were 1646 meters above the sea level, the sunset occurred at 18:54. The Moon will set after 34 minutes of the sunset, and the topocentric (NOT geocentric) new moon from Al-Shoubak occurred on Friday 10 September at: 00:37 local time. So at the sunset, the topocentric age of the crescent was 18:17 (hours:minutes). At that time we entered the coordinates of the Moon, which were: (R.A.: 11:49:49 , Dec.: 04:12:11) We got them from the program RedShift 2.0. The telescope moved automatically to the given coordinates. We used 10-inch Meade LX200 telescope (f/10), and the eyepiece was 56 mm Meade Super Plossl. The magnification was 45X, and the field is 1.16 degrees. VERY surprisingly at 19:00 local time, which is after 6 minutes of the sunset, I noticed a bright VERY thin thing in the eyepiece !!!! WOOOOW It was the crescent !!!! I was shouting then !!! I left the telescope and started jumping :-) !

It was VERY VERY hard to be seen ! Directly, Shweiki looked into the eyepiece ! Even though, he is an experienced observer, but he spent more than 30 seconds until he could see the crescent ! After him, Alawneh and Katbeh looked into the eyepiece and they saw the crescent. In addition, there were some guests with us. They were persons who live in that area. They are not amateurs for sure, and they were amazed to see such very thin crescent. All of them saw the crescent. Later on, the crescent became a bit easier to be seen, and we could see it more clearly through the telescope. The difference of its brightness from area to another was very clear, and it was not lit in some areas ! It was really as twine or piece of hair ! We tried to see it by binoculars and by naked eyes, but we couldn't ! But we took photos for it through the telescope. I took wide range of exposures, but it was VERY hard to detect in the photo due to the low contrast between the crescent and the sky. We had a strong feeling that if the western horizon was not that clear (Such as Amman), or if it was smaller than this one, then we would not see the crescent ! Observers in Amman reported that they didn't see the crescent. Knowing that they were using binoculars only. Persons who saw the crescent were:-

1. Marwan Shweiki.
2. Mohammad Odeh.
3. Mohammad Alawneh.
4. Tarek Katbeh.
5. Eng. Hussien Marwan.
6. Eng. Taha Al-Hlalat.
7. Hasan Al-Hlalat.
8. Abdul-Kareem Amareen.

* The Moon at Sunset (At Al-shoubak):-

• Date: 10 September 1999.
• Sunset: 18:54 LT (UT + 3).
• Topocentric Age: 18:17 (hours:minutes).
• Geocentric Age: 17:52.
• Altitude: 05:45 (degrees:minutes).
• Altitude (Above the apparent horizon, due to our elevation): 07:01.
• Sun's azimuth minus Moon's azimuth: 05:09 (degrees:minutes).
• The Moon sets after the sunset by: 34 minutes.

* Observer in Amman were:-

1. Moh'd Murad
2. Ahmed Al-Naimat
3. Khalid A-Tell
4. Mrs. Sana'a Abdo
5. Ahmed Abdo
6. Hamza Abdo
7. Ms. Basma Diab
8. Eng. Khalil Konsul
9. Khalid Eid
10. Husam Eid
11. Waleed Abu-Alyia

Finally, I'd like to mention the accuracy of the astronomical calculations !!! Many persons attributed the calculations to be inaccurate ! Especially at Ramadan or Shawwal, when the calculations shows that the crescent is impossible to be seen, while some witnesses claim seeing the crescent ! This example clearly shows the EXTREME ACCURACY of the calculations ! Notice that we got the coordinates of the Moon from an Astronomy software, so if the coordinates were inaccurate, then the telescope won't point at the crescent ! Especially if we know that the field of the telescope was 1.16 degrees !!! The sky from East to West is 180 degrees, while the field of the telescope was about 1 degree ONLY !! That means if the coordinates of the Moon were in an error of one degree then we won't see the crescent !!! Notice that as we entered the coordinates and the telescope moved, we found the crescent in the center of the field !!! That means also, the telescope is so accurate ! If it has an error of 0.5 degrees then we won't see the crescent ! Notice also, that we were NOT searching for the crescent !! The telescope got it in its field, and we were just looking in the field ! Nevertheless, we spent long time until we could detect it ! After this example, who still insists on attributing the calculations to be inaccurate, then he is clearly does not realize what he is reading!

Photos for The Camp

The crescent at the circle's center It looks like the black curve at left Fuji 400, 1/8 second, By Moh'd Odeh	The Predicted Crescent As predicted by the Program Moon Calculator 5. By Dr. Monzur Ahmad.
Observing the Sun for the gusts Notice the western horizon. The clouds are below the horizon !	At Morning Taking the breakfast Among Al-Shobak Mountains

Reactions

• Dr. Monzur Ahmed (UK): "Congratulations on your crescent sighting on the evening of 10th Sept 1999! You were on the very edge of possibility......... Again, congratulations to you and all in your team for such a difficult sighting."

• Mr. Saleh Al-Saab (Saudi): "Congratulations, congratulations, I am very happy that one teem of (ICOP) could see the crescent."

• Mr. Georg Dittie (Germany): "Congratulations to your extreme early moon sighting you reported to the mailing list. I've read your report with excitement and enjoyed the images from your observing site."

• Dr. John Caldwell (South Africa): "First off congratulations on the sighting. I was relieved and rather pleased that it comes in okay with our SAAO criteria, just above the LOWER line which is

  "remotely possible with optical aid but not with naked eye" in the sense of improbable but NOT IMPOSSIBLE with optical aid

  In fact it seems to define the edge of what is just marginally possible with a telescope; any harder and you wouldn't have seen it right? and the conditions were superb."

• Mr. Mohamed Khadraoui (Tunisia): "Congratulations !"

• Mr. Khalid Shaukat (USA): "I appreciate your team effort to sight this extremely difficult moon from your area. Keep up the good work."