-
NGC/IC: Numbers in this column
represent the NGC number of the object. If the object is not an NGC
object, the prefix of the catalog is used. For example: IC418, H15, and
Mel25.
-
Messier: If the object part of the
Messier catalog, its Messier number will be listed in this column.
-
Const.: This column contains the
abbreviation of the constellation= where the object is located.
-
Type: The type of object can be one of
the following: OC Open Cluster, GC Globular Cluster, GX Galaxy, NB Nebula,
PN Planetary Nebula, CN Star Cluster with Nebulosity, ST Start Asterism or
Double Star.
-
R.A.: This is the right ascension
coordinate of the object.
-
Dec.: This is the declination
coordinate of the object.
-
Mv: This column is the visual magnitude
of the object.
-
Size: This is the size of the object
measured at its widest. The = size measure is in arc minutes.
-
No *: This column represents the number
of stars found in open clusters.
-
GX Type: This is the galaxy type. The
possible values are: E Elliptical, S Spiral, Irr Irregular, SB - Barred
Spiral, dE - Dwarf Elliptical, S0 and SB0 - Lenticular. The numbers or the
lower case letters following the main classification are secondary
classification types.
-
Level: This column contains a number
from 1 to 5. It represents the difficulty level number. The level 1
objects are the easiest objects and level 5 are the hardest.
-
Observe: This column represents the
date range to observe the object. For an object to have dates in this
column, it has to be at least 5 degrees above the horizon at some point in
time during astronomical night. If an object has value `All Year', it
means that the object is at least 5 degrees above the horizon at some
point in time during astronomical night every day of the year. If the
object has a date range such as `May12-Nov18', it means that May 12 is the
first day the object is 5 degrees above the horizon in the morning when
the astronomical night ends. November 18 is the last day in the evening
that the object will be 5 degrees above the horizon when the astronomical
night starts. If an object has this value `-` in the Observe column, it
means there are no days during the year that the object is at least 5
degrees above the horizon during astronomical night.
-
Meridian: This column list the best
time to observe an object. It= lists the date range the object passes the
south meridian during astronomical night. It consists of three dates. The
first indicates the day the object is straight South or straight North
higher than Polaris (in other words when the object is at its highest in
the sky) at the end of astronomical night. The middle date is when the
object is at its highest in the sky at midnight EST or 1am EDT in Ottawa.
The third date is when the object is at its highest is the sky when the
astronomical night starts.
-
Photo: This column represents the date
range to photograph the object. It is very similar to the Observe column.
The date range in Photo means the object is at least 10 degrees above the
horizon at some time during the night from 15 minutes after the
astronomical
night starts until 15 minutes before the end of astronomical night. The 15
minutes offset was chosen for this column to allow for a 15 minutes
exposure.
-
Name: This is the common name of the
object.
