Now that I have a telescope, I need to find something to look at in the sky. Saturn and Jupiter were pretty easy to find since they are so bright. Nevertheless, the first photos taken look ugly. I compiled a list of potentially interesting targets. Let’s see, if I can find and recognize them.
Some remarks to the following text
- All terrestrial position related times in here are given for Mainz, Germany (50°N/8°E) if not mentioned otherwise.
- The sun and moon tables are updated daily.
- I sometimes write ‘stars’ as synonym for all objects also including galaxies and nebulas.
Astronomical coordinate system
This applies only to objects outside our solar system. Those in our solar system are to fast.
The equator is always at 0° declination, which means in Mainz (50°N) I can neglect everything with a declination close and less than -40° since those objects never cross the horizon and those with a declination larger than 50° will be visible the whole night. The 0h ascension “angle” is defined by the sun at the 21. March 12 GMT, more on the right ascension under Season.
Finding the right time
To see the stars there should be no clouds in the sky. One can look out the window, at a cloud forecasts/weather app on the smartphone or visit the webpage of your confidence, e.g.
Sunrise/-set and twilight
It should be dark, therefore late enough. After the sunset, when the sun disappeared behind the horizon, it is not immediately dark. It will be ‘totally’ dark after the astronomical twilight, which is when the sun is 18° below the horizon. Nevertheless, lay astronomers like me may start earlier in the evening or later in the morning.
Based on the sun’s angle relative to the horizon there are also a few other definitions/agreements.
- astronomical twilight < 18° below horizon
- nautical twitlight < 12° below horizon (not listed here)
- blue hour 8° - 4° below horizon
- civil twilight < 6° below horizon
- golden hour 6° below and above horizon
This table here shows the times for the current day:
As long as I don’t want to see the moon, I should try to look at the stars before the moon rise, after moonset or the days at around new moon. At full moon the moon shines the whole night long, and with each following day the moon rises ~50 minutes later. Below is a figure with the moon rise, culmination, set moon phase and distance from earth in km for yesterday and the next 14 days.
Or use other ressources in the world wide web:
Equally to the sun, the stars reach their highest position (culmination) over the horizon on the northern hemisphere in the south. And (like the sun on noon at midsummer) each star has once a year a maximum culmination. Not surprisingly this is contrary to the sun at midnight.
This maximum culmination can be estimated from the right ascension (RA, German: “Rektaszension”), which is given in hours. 0h is defined as the direction towards the sun on the 21. March 12:00 GMT. This means stars with a right ascension of ~12h reach their maximum culmination (at midnight) in spring, ~18h in summer, ~0h in autumn and ~6h in winter. If I want to see the star’s culmination before midnight, I must do that after the maximum culmination. If I want to see the culmination before the date of maximum culmination I either have to stay up very long or wake up very early.
I collected all the data from Wikipedia. Sometimes the coordinates there were given with several decimal places. I rounded them, since it does not make sense with several orders of magnitude between extent and the precision of the coordinates.
The further south the objects are and the less bright they are, it’s getting harder to spot them. The brightness is given as apparent magnitude (m): the lower the number the brighter they are. Polaris (marking the north pole) has an apparent magnitude of ~2, the sun of ~-26. The human eye has a limit around 4-7. For my 127mm telescope the limiting aperture is ~13.
I will extend the list below with the objects and give it a color code, with
- blue: seen with the naked eye
- green: seen with binoculars
- yellow: easily seen with the telescope
- orange: harder to find
- red: Hmm, did I really see it or was it my imagination
|Mesarthim||double star||1h 53m 32s||19° 17' 38"||4|
|Theta Tauri||double star||4h 28m 34s||15° 57' 44"||4|
|Rigel||double star||5h 14m 32s||-8° 12' 6"||7|
|Alnitak||double star||5h 40m 46'||-1° 56' 34"||2|
|Porrima||double star||12h 41m 40s||-1° 26' 58"||3|
| Mizar and|
|double star|| 13h 23m 55s|
13h 25m 14s
| 54° 55' 31"|
54° 59' 17"
|Algieba||double star||10h 19m 58s||19° 50' 29"||2|
|Epsilon Lyrae||double star||18h 44m 20s||39° 40' 12"||5|
|Albireo||double star||19h 30m 43s||27° 57' 35"||6|
|NGC 869 + 884||double cluster||2h 19m 6s||57° 9'||4||30'|
|M 45 (Pleiades)||open cluster||3h 47m 24s||24° 7'||2||110'|
|Hyades||open cluster||4h 27m||15°52'||0.5||330'|
|NGC 1893||open cluster||5h 22m 44s||33° 24' 4"||8||11'|
|M 38||open cluster||5h 28m 43s||35° 51' 18"||7||21'|
|M 36||open cluster||5h 36m 18s||34° 8' 24"||6||10'|
|M 35||open cluster||6h 8m 54s||24° 20'||5||28'|
|NGC 2419||globular cluster||7h 38m 9s||38° 52' 55"||9||6'|
| M 44 |
|open cluster||8h 40m 24s||19° 59'||4||95'|
|M 3||globular cluster||13h 42m 12s||28° 22' 38"||6||18'|
|M 4||globular cluster||16h 23m 35s||26° 31' 33"||6||26'|
|M 13||globular cluster||16h 41m 41s||36° 27' 35"||6||20'|
|M 6 (Butterfly)||open cluster||17h 40m 6s||-32° 13'||4.2||25'|
|M 92||globular cluster||17h 17m 7s||43° 8' 9"||6||14'|
|M 16 (Eagle)|| open cluster|
|18h 18m 48s||-13° 49'||6||60'|
|M 22||globular cluster||18h 36m 24s||-23° 54' 12"||5||0.53'|
|NGC 6633||open cluster||18h 27m 42s||6° 34'||5||27'|
|M 11 (Wild Duck)||open cluster||18h 51m 5s||-6° 16' 12"||6||23'|
|M 54||globular cluster||18h 55m 3s||-30° 28' 48"||8||12'|
|M 15||globular cluster||21h 29m 59s||12° 10' 1"||6||0.3'|
|M 2||globular cluster||21h 33m 27s||-0° 49' 24"||6||0.27'|
| M 31 |
|galaxy||0h 42m 44s||41° 16' 9"||3||3°|
| NGC 253 |
|galaxy||0h 47m 33s||-25° 17' 18"||8||27'|
| M 33 |
|galaxy||1h 33m 50s||30° 39' 36"||6||71'|
| M 81 |
|galaxy||9h 55m 33s||69° 3' 55"||7||20'|
| M 82 |
|galaxy||9h 55m 52s||69° 40' 47"||8||10'|
| M 51 |
|galaxy||13h 29m 53s||47° 11' 43"||8||11'|
| M 101 |
|galaxy||14h 3m 13s||54° 20' 57"||8||28'|
| M 104 |
|galaxy||12h 39m 59s||-11° 37' 23"||8||9'|
| NGC 281 |
|nebula||0h 52m 59s||56° 37' 19"||7||35'|
| M 76 |
|nebula||1h 42m 24s||51° 34' 31"||10||2'|
|NGC 896 (Heart)||nebula||2h 33m 22s||61° 26' 36"||7||150'|
|IC 1848 (Soul)||nebula||2h 55m 24s||60° 24' 36"||7||150'|
| NGC 1499 |
|nebula||4h 3m 18s||36° 25' 18"||6||150'|
| IC 405 |
|nebula||5h 16m 5s||34° 27' 49"||6||37'|
|M 42 (Orion)||nebula||5h 35m 17s||-5° 23' 28"||4||65'|
|NGC 2024 (Flame)||nebula||5h 41m 54s||-1° 51' 0"||10||30'|
| IC 434 |
|nebula||5h 41m 1s||-2° 27' 14"||11||60'|
| NGC 2174 |
|nebula||6h 9m 42s||20° 30'||7||40'|
| NGC 2237 |
|nebula||6h 33m 45s||4° 59' 54"||9||78'|
| NGC 2392 |
|nebula||7h 29m 11s||20° 54' 42"||10||0.8'|
|M 97 (Owl)||nebula||11h 14m 48s||55° 1' 9"||10||3'|
| NGC 6543 |
|nebula||17h 58m 33s||66° 37' 59s||10||0.33'|
|M 20 (Trifid)||nebula||18h 2m 23s||-23° 1' 48"||6||28'|
|M 8 (Lagoon)||nebula||18h 3m 37s||-24° 23' 12"||6||90'|
|M 57 (Ring)||nebula||18h 53m 35s||33° 1' 45"||9||4'|
|M 27 (Dumbbell)||nebula||19h 59m 36s||22° 43' 16"||8||8'|
| NGC 6888 |
|nebula||20h 12m 7s||38° 21' 18"||7||18'|
|NGC 6960 (Veil)||nebula||20h 45m 38s||30° 42' 30"||7||180'|
| IC 1396 |
|cluster + nebula||21h 38m 58s||59° 29' 18"||4||150'|
| NGC 7662 |
|nebula||23h 25m 54s||42° 32' 6"||9||0.62'|
Although the Andromeda galaxy is visible with binoculars, the view through the telescope was a bit disappointing. The blurred spot of milk was just bigger. Maybe due to bad seeing or let’s see if I can train my eyes to see more details in the future.
Alcor is called “Reiterlein” in German because it is smaller and “rides” on Mizar.
Add-on 2021-11-07: Calculation of camera-sensor/lens parameters
To check, if a target fits on my camera sensor, I’ve created an extra page just with a table calculating the angle of view (AOV) and maximum exposure time for varying focal length and sensor layouts fitting on a smartphone screen.
- 10 Himmelsobjekte für Einsteiger und Anfänger
- Die schönsten Deep-Sky-Objekte für Anfänger
- Astronomie-mainz.de: Deep-Sky
- Helligkeit & Größenklasse
- Limiting Magnitude Table
- Astrofotografie: Nebel
- Teleskop-ABC (Free-book from the telescope seller)
- The above times for the sun- and moonrise/-set and moonphases were calculated daily with the python package pyephem