Across much of the world, the Butterfly open star cluster (M6, NGC 6405; mag 4.2) in Scorpius will be well placed in the evening sky in coming weeks. On 16 June it will reach its highest point in the sky at around midnight local time, and on subsequent evenings it will culminate four minutes earlier each day.
From Cambridge , however, it is not readily observable since it lies so far south that it will never rise more than 15° above the horizon.
At a declination of 32°15'S, it is easiest to see from the southern hemisphere but cannot be seen from latitudes much north of 37°N.
At magnitude 4.2, M6 is tricky to make out with the naked eye except from a dark site, but is visible through a pair of binoculars or small telescope.
The position of M6 is as follows:
| Object | Right Ascension | Declination | Constellation | Magnitude | Angular Size |
| M6 | 17h40m20s | 32°15'S | Scorpius | 4.2 | 0'00" |
The coordinates above are given in J2000.0.
The sky on 17 Jun 2021
| The sky on 17 June 2021 | ||||||||||||||||||||||||||||||||||
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44% 7 days old |
All times shown in EDT.
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Source
The circumstances of this event were computed using the DE430 planetary ephemeris published by the Jet Propulsion Laboratory (JPL).
This event was automatically generated by searching the ephemeris for planetary alignments which are of interest to amateur astronomers, and the text above was generated based on an estimate of your location.
Image credit
© Digitised Sky Survey (DSS); Second Palomar Observatory Sky Survey (POSS-II)