© Digitised Sky Survey (DSS); Second Palomar Observatory Sky Survey (POSS-II)

The Ptolemy cluster is well placed

Dominic Ford, Editor
From the Deep Sky feed

Objects: M7
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The Ptolemy Cluster (M7, NGC 6475; mag 3.3) in Scorpius will be well placed in the evening sky in coming weeks. On 20 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 Washington , it is difficult to observe as it will appear no higher than 18° above the horizon. It is visible between 00:29 and 02:35. It will become accessible at around 00:29, when it rises to an altitude of 16° above your southern horizon. It will reach its highest point in the sky at 01:32, 18° above your southern horizon. It will become inaccessible at around 02:35 when it sinks below 16° above your southern horizon.

At a declination of 34°47'S, it is easiest to see from the southern hemisphere but cannot be seen from latitudes much north of 35°N.

Begin typing the name of a town near to you, and then select the town from the list of options which appear below.

At magnitude 3.3, M7 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 M7 is as follows:

Object Right Ascension Declination Constellation Magnitude Angular Size
M7 17h53m50s 34°47'S Scorpius 3.3 0'00"

The coordinates above are given in J2000.0.

The sky on 20 Jun 2021

The sky on 20 June 2021
Twilight ends
Twilight begins

10-day old moon
Waxing Gibbous


10 days old

Rise Culm. Set
Mercury 05:37 12:38 19:39
Venus 07:53 15:12 22:31
Moon 16:28 22:07 03:38
Mars 09:01 16:08 23:16
Jupiter 00:28 05:55 11:22
Saturn 23:32 04:39 09:46
All times shown in MDT.


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)





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