Planetary nebula · Delphinus
NGC 6905 Blue Flash Nebula
mag 11.142″ across
About
NGC 6905, the Blue Flash Nebula, is a planetary nebula of magnitude 11.1 in Delphinus, about 42″ across.
How to find it
- NGC 6905 is in the constellation Delphinus.
- Best evenings: around mid-September it is highest at about 9 pm (10 pm in summer time); a month earlier, two hours later.
- Where on Earth: it is seen well, at least 10° up, from north of 60° S.
When it rises and sets tonight, how high it climbs and how much the Moon gets in the way are worked out in your browser for your place.
What you will see
- EyesNot visible to the naked eye.
- Binoculars (10×50)Too faint for binoculars.
- Telescope (6–8 inch)A faint round glow — a UHC or OIII filter makes it much easier.
For a dark country sky with no Moon. From a city, faint galaxies and nebulae can disappear completely.
Facts
| Designations | NGC 6905, PN G061.4-09.5 |
|---|---|
| Type | Planetary nebula |
| Magnitude | 11.1The smaller the number, the brighter. |
| Apparent size | 42″the full Moon is 31′ across |
| Surface brightness | ≈ 19.0 mag/arcsec²Estimate from the magnitude and size, per square arcsecond. |
| Constellation | Delphinus |
| Right ascension (J2000) | 20h 22m 23.0s |
| Declination (J2000) | +20° 06′ 16″ |
Sources and credits
Catalog data: OpenNGC by Mattia Verga, CC BY-SA 4.0, and d3-celestial by Olaf Frohn, BSD 3-Clause. All data sources →