general search keywords -negatedkeyword "multi word expression" -"negated multi words"

catalog:K - where K may be M, C, NGC, PGC, UGC, IC, messier, caldwell, Abell, Sharpless, SH2, Collinder, Col, Melotte, Mel, Arp

minmag:M, maxmag:M - limit magnitude (the catalog is big)

minlum:M, maxlum:M - limit magnitude, maxlum=minmag, minlum=maxmag

mindec:D, maxdec:D - limit declination

:mayrise - limit to objects with suited declination-latitude pairing; can be negated

:onsky - limit to objects above the horizon, assuming Bucharest time and CJ as location

sortby:S - can be size, mag[nitude], c[aldwell], m[essier], or "catalog" if catalog:K was specified

type:T - can be oc,gxy,gc,neb; can be negated

minsize:D - many objects have size data. D is degrees

yearof:RA_DEG,DEC_DEG - walk through the next 365 days to find the max altitude in darkness, taking into account the sun, the moon and the geolocation of the viewer

yearof:search_string - as above, the first result's coordinates are processed

monthof:RA_DEG,DEC_DEG - walk through the next 32 days to find the max time in darkness, above 20 deg, taking into account the sun, the moon and the geolocation of the viewer

monthof:search_string - as above, the first result's coordinates are processed

const:T - constellation, should be the international abbreviation, but also works with some common names

:context - context:10min, see below

context:C - list objects around result's radius C arc minutes sorruondings

contexttype:CT - limit context objects to CT type

contextcatalog:CT - limit context objects to CT catalog

minaltindarkness:D - limit to objects that reach at least altitude D in degrees while the Sun is below -18 degrees altitude and the moon is below +1 deg.

at:ra,dec,radius - search for objects at given position within given radius. The implicit unit is degree (decimal format), but many formats can be given. Like at:XXhXXmXXs,XXdXXmXXs,0.2rad ie hour-minute-second, degree-arcminute-arcsecond, radians

:zenith, at:zenith - search for objects around the zenith, default radius is 10 deg

at:zenith,radius_deg - search for objects around the zenith with radius

HH MM SS SDD MM SS - raw coordinates invoke an at:HHhMMmSSs,DDdMMmSSs,tolerance search. Tolerance needed due to floating point values.

niceasphoto:F - looks nice at focal length F with Canon APS-C senzor (a common setup). For F I use values, 18, 50, 135, 200, 400, 600, 750, 1200, the most common being 200 and 750. This is my personal and incomplete selection. Use it like what it is.


Approximate position of the Sun
:sun explain

Approximate position of the Moon
:moon explain

List Messier objects around M31 in a 5 degree radius:
m31 context:5deg contextcatalog:m explain

List messier and caldwell objects, accessible from the observer\'s geolocation, that are nebulous, sorted by magnitude (default)
nebula catalog:c,m :onsky explain

List Caldwell objects brighter than or equal to 7 magnitudes which are at least 35 degrees high on the sky of the observer (location checked with GPS, defaults to CJ), sorted by altitude (current time)
minalt:35deg catalog:caldwell minlum:7 sortby:alt explain

List Caldwell objects brighter than or equal to 7 magnitudes which are at least 35 degrees high on the sky of the observer (location checked with GPS, defaults to CJ), sorted by altitude (current date, optimized to maximum altitude in darkness)
minaltindarkness:35deg catalog:caldwell minlum:7 sortby:maxaltindarkness explain

List objects brighter than or equal to 6 magnitudes which are always below the horizon from the observer, sorted by brightness
horizon:0 minlum:6 sortby:mag explain

List Messier objects sorted by Messier number
catalog:m sortby:catalog explain

List Caldwell objects sorted by Caldwell number
catalog:c sortby:catalog explain

List M101, M81 and M82\'s NGC context
m101,m81,m82 context:3deg contextcatalog:ngc explain

List Messier objects around M31, 15 degrees
m31 context:15deg contextcatalog:m explain

List the Sharpless 2 catalog (no sorting by catalog number available - the items are scattered around the db, no own column)
catalog:sh2 explain

Messier and Caldwell objects for this night, this geolocation
catalog:mc :nicefortonight explain

List Messier and Caldwell objects, sorted by max time in darkness then magnitude
catalog:mc sortby:maxdarktimemag explain

List Caldwell objects below the equator, sortby Caldwell number
catalog:caldwell maxdec:0 sortby:catalog explain

List some known asterisms. Some are obvious (like the Owl Cluster), some are like wtf, but someone put them in a table
:asterisms explain

List nearby stars. Sun excluded. Other search words are ignored in this case. Sorted by distance, nearest first.
:listnearbystars explain

List nearby stars, the first ten. Sun excluded. The upper limit is 1000. Other search words are ignored in this case.
:listnearbystars 10 explain

List the 10 brightest stars on the sky. Sun excluded. The upper limit is 1000. Other search words are ignored in this case.
:listbrighteststars 10 explain

Regions. Spring, summer, autumn, winter plus northern and southern, plus equatorial and polar are accepted. Look for autumn Messier objects
region:autumn catalog:m explain

Regions. Messiers below the equator
region:southern catalog:m explain

Regions. Messier and Caldwell objects near the poles
region:polar catalog:mc explain

List planetary nebulae from the Caldwell and Messier catalog
catalog:mc type:pn sortby:mag explain

List galaxies from the Caldwell and Messier catalog
catalog:mc type:galaxy sortby:mag explain

List nebulous objects marked to be nice photo targets, that rise to above 20 deg
nebulae :niceasphoto minaltindarkness:20 explain

List non-Messier and non-Caldwell objects that have been marked to be nice as photo targets at any focal length
-catalog:mc niceasphoto:* explain

List nice photo targets for 200mm, that are available tonight
niceasphoto:200 minaltindarkness:30 explain

Some other shortcuts are :nicenebulae :niceclusters :nicegalaxies :niceplanetaries. Try this one:
:niceglobulars :onsky minaltindarkness:35 explain

Nice targets for this night, from this geolocation
:nicefortonight explain

Nice spiral galaxies for tonight, from this geolocation
:nicespirals minaltindarkness:35 explain

Nice spiral galaxies, clear previous plots and plot the search results
clearplot: :nicespirals explain

List nice photo target galaxies for 200 and 750, that reach at least 25 degrees altitude while the Sun is below -18 degrees.
:nicegalaxies:200~750:25 explain

List galaxies around the Needle galaxy (NGC 4565)
needle galaxy context:1deg contexttype:galaxy explain

List objects of type galaxy that are target candidates for here-and-now at a given focal length. The targetfor:750 is a shorthand for targetfor:750
targetfor:750 type:galaxy explain

Photogeny means reasonable time (in hours) in darkness at reasonable altitude. List galaxies that are photogenic here-and-now from the Messier and Caldwell catalogs
type:galaxy minphotogenytime:3 catalog:mc explain

Photogenic object for one hour for a 750mm setup (assuming APS-C senzor)
targetfor:750 minphotogenytime:1 maxphotogenytime:1 explain

List DSOs in Andromeda (constellation) brighter than 10 magnitudes
const:andromeda minlum:10 explain

List DSOs brighter than 10 magnitudes available at the geolocation of the observer
minlum:10 :onsky sortby:mag explain

Select DSOs that based on their luminosity, size and position, the user's position and the position of the Sun and the Moon, are ready to be photographed. This means the objects reach a certain height above the horizon while the Sun is still below -18 degrees, ie full night, and are far from the Moon.
:phototargets explain

View exact coordinates, no other arguments accepted. Format: HH MM SS SDD MM SS
08 40 24.000 +19 39 60.0 explain

IF in the photo planner, use plot: to add or clearplot: to remove-all-previous-then-add a marker for each search result. Plot Messier and Caldwell objects of a minimum luminosity of 8mag.
plot: catalog:mc minlum:8 explain

IF in the photo planner, you can plot the exoplanets (the list is from the wiki)
clearplot:exoplanets explain

IF in the photo planner, go to the zenith, here, now
goto:zenith explain

List odd Abell planetary nebulae catalog members - that are no planetaries. A curiousity
catalog:abell -type:pn explain

List the viewing conditions for the Pleiades
yearof: m45 pleiades explain

List the viewing conditions for the Pleiades, coalescing above 42 degrees
yearof: m45 pleiades coalesceabove:42 explain

List the time in darkness for the M51, for the next month
monthof: m51 explain

List the time in darkness for the M84, for the next month
monthof: m84 explain

List the time in darkness for the M31, for the next month
monthof: m31 explain