Sketch a spring deep-sky ob­ject

Sky at Night Magazine - - SPRING OBSERVING -

Dif­fi­culty level: Be­gin­ner and up

Ex­plor­ing the spring night skies through the eye­piece of a tele­scope can be a mag­i­cal ex­pe­ri­ence as you hunt down ghostly gal­ax­ies and bright glob­u­lar clus­ters with their ex­quis­ite gran­u­lar forms. As­tropho­tos can cap­ture the special qual­i­ties of these ob­jects, pro­vid­ing spec­tac­u­lar, de­tailed views the likes of which our eyes could never see. But even in this age of CCD cam­eras and dig­i­tal pho­tog­ra­phy, there’s still some­thing to be said for sim­ply sketch­ing what you see through your eye­piece with an old-fash­ioned pen­cil.

Not only can sketch­ing be a fun way to record what you’ve seen for your own mem­o­ries, but it can also be use­ful for giv­ing other ama­teur as­tronomers – par­tic­u­larly those just start­ing out – an in­di­ca­tion of the sort of thing they can ex­pect to see through equip­ment com­pa­ra­ble to your own. This is es­pe­cially true of the nu­mer­ous faint gal­ax­ies scat­tered across the spring skies, which of­ten ap­pear in long-ex­po­sure astro im­ages as shin­ing swathes of light fes­tooned with in­tri­cate de­tails, when, in fact, the view through the eye­piece of a mod­est tele­scope is usu­ally quite dif­fer­ent.

Sketch­ing, at its most ba­sic, re­quires some pa­per, a good pen­cil and some­thing to rest on while you draw at the eye­piece. If it’s some­thing you think you’ll en­joy do­ing of­ten you can in­vest in a good-qual­ity artist’s sketch pad with heavy­weight pa­per, be­cause reg­u­lar pa­per is likely to wrin­kle dur­ing long sketch­ing ses­sions out­side. And as for pen­cils, you can usu­ally ex­e­cute most as­tro­nom­i­cal sketch­ing tech­niques with just a good-qual­ity 2B pen­cil. A de­cent eraser is handy, too.

Be­fore sketch­ing you should al­low your eyes to be­come fully dark-adapted and, if pos­si­ble, use a re­ally dim, red, light-source – like a head torch cov­ered in red ac­etate or red sweet wrap­pers – to draw by.

There are plenty of spring ob­jects that make good tar­gets for sketch­ing, from any of the bright glob­u­lar clus­ters we men­tioned in the first pro­ject to brighter gal­ax­ies like M64 in Coma Berenices and the pair­ing of M65 and M66 in Leo.

To be­gin, draw a cir­cle on your pa­per to rep­re­sent the edge of your eye­piece’s field of view. Once ob­serv­ing at the tele­scope, start by mark­ing the po­si­tions of the brighter – then fainter – stars in the field of view, pay­ing par­tic­u­lar at­ten­tion to the rel­a­tive dis­tances and an­gles be­tween them. When you have the star field in place, be­gin sketch­ing in your cho­sen deep-sky tar­get. For gal­ax­ies use the side of the pen­cil lead to gen­tly add graphite to the pa­per, blend­ing and smudg­ing with your fin­ger­tip to pro­duce a fuzzy ap­pear­ance if nec­es­sary. For glob­u­lar clus­ters, gen­tle stip­pling can be an ef­fec­tive way to ren­der the myr­iad stars at their cores.

Re­mem­ber to draw ‘in­verted’; the dark pen­cil marks on the pa­per rep­re­sent where you see light in the eye­piece. You can scan the sketch later and in­vert it in im­age­pro­cess­ing soft­ware, mak­ing your draw­ing look like the view in the eye­piece.

A sketch of M13, with gen­tle stip­pling recre­at­ing the glob­u­lar clus­ter

This sketch of M105 was orig­i­nally black on white, but now in­verted

First map out the ma­jor stars, then add in your deep sky ob­jects

Start by draw­ing a cir­cle to rep­re­sent your eye­piece’s field of vi­sion

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