The RASC's Deep Sky Challenge Objects list

The Royal Astronomical Society of Canada (RASC) has published this list in their yearly Observer's Handbook which is edited by James S. Edgar. The Deep Sky Challenge Objects List was compiled by Alan Dyer and Alister Ling; it is arranged by right ascension.
Credit: Royal Astronomical Society of Canada (RASC)

Object Descriptions


No. Object       Con  Type    R.A.     Dec     m_v    Size      U2#  min.A
                                                 
 1  NGC 7822     Cep  E/RN    00:03.6  +68:37   -      60x30      8  30     
 2  IC 59        Cas  E/RN    00:56.7  +61:04   -      10x5      18  20-25
 3  NGC 609      Cas  OC      01:37.2  +64:33  11.0     3.0      17  25-30
 4  IC 1795      Cas  EN      02:24.7  +61:54   -      27x13     29  20
 5  Maffei 1     Cas  G-E3    02:36.3  +59:39  ~14      5x3      29  30
 6  NGC 1049     For  GC      02:39.7  -34:29  11.0     0.6     175  25-30
 7  NGC 1275     Per  G-Pec   03:19.8  +41:31  11.6   2.6x1.9    43  20-25
 8  NGC 1432/35  Tau  RN      03:46.1  +23:47          30x30      78 10-15
 9  IC 342       Cam  G-SBc   03:46.8  +68:06  ~12     17x17     16  20-30
10  NGC 1499     Per  EN      04:00.7  +36:37         145x40     60  8-12.5 RFT

11  IC 405       Aur  E/RN    05:16.2  +34:16          30x19     59  20
12  HH 1         Ori  E       05:36.3  -06:45 ~14.5      8"     136  25
13  IC 434/B 33  Ori  E/DN    05:40.9  -02:28          60x10    116  15-20 dark sky!
14  Sh 2-276     Ori  EN      05:48    +01            600x30!   116  10-15 RFT
15  Abell 12     Ori  PN      06:02.4  +09:39  ~13     37"       96  25-30
16  IC 443       Gem  SNR     06:16.9  +22:47          50x40     76  25-30
17  J 900        Gem  PN      06:25.9  +17:47  12.2     8"       76  20
18  IC 2177      Mon  E/RN    07:05.1  -10:42         120x40    135  20-30
19  PK 205+14.1  Gem  PN      07:29.0  +13:15  ~13    ~700       95  20-25

20  PK 164+31.1  Lyn  PN      07:57.8  +53:25  ~14    6'40"      26  25
21  Leo I        Leo  G-E3    10:08.4  +12:18   9.8   10.7x8.3   93  30
22  Abell 1367   Leo  G's     11:44.0  +19:57  13-16  ~60        72  30-40
23  NGC 3172     UMi  G-?     11:50.2  +89:07  13.6   0.7x0.7     1  25
24  NGC 4236     Dra  G-SBb   12:16.7  +69:28   9.6   18.6x6.9   13  20-25
25  Mrk 205      Dra  Quasar  12:21.6  +75:18  14.5   stellar     5  30
26  3C 273       Vir  Quasar  12:29.1  +02:03  12-13  stellar   111  25-30
27  NGC 4676     Com  G's     12:46.2  +30:44  14.1p  ~ 2x1      53  25
28  Abell 1656   Com  G's     13:00.1  +27:58  12-16  ~60        71  25-30
29  NGC 5053     Com  GC      13:16.4  +17:42   9.8    10.5      71  10-20
30  NGC 5897     Lib  GC      15:17.4  -21:01   8.6    12.6     148  15-20
31  Abell 2065   CrB  G's     15:22.7  +27:43  ~16    ~30        69  50 in superb sky!
32  NGC 6027     Ser  G's     15:59.2  +20:45  ~15    ~ 2x1      69  40
33  B 72         Oph  DN      17:23.5  -23:38          30       146  8-12.5 RFT
34  NGC 6791     Lyr  OC      19:20.7  +37:51   9.5    16        48  20-25
35  PK 064+05.1  Cyg  PN      19:34.8  +30:31   9.6     8"       48  20
36  M 1-92       Cyg  RN      19:36.3  +29:33  11.0   12"x6"     48  25-30
37  NGC 6822     Sgr  G-Irr   19:44.9  -14:48  ~11    10.2x9.5  125  10-15
38  Palomar 11   Aql  GC      19:45.2  -08:00   9.8     3.2     125  20-30
39  IC 4997      Sge  PN      20:20.2  +16:45  10.9     2"       84  20
40  IC 1318      Cyg  EN      20:26.2  +40:30         large      32  8-15 RFT
41  PK 080-06.1  Cyg  PN?     21:02.3  +36:42  13.5    16"       47  25
42  IC 1396      Cep  EN      21:39.1  +57:30         170x140    19  10-12.5 RFT
43  IC 5146      Cyg  E/RN    21:53.5  +47:16          12x12     31  20-25
44  NGC 7317-20  Peg  G's     22:36.1  +33:57  13-14  ea.~1      46  25-30
45  Jones 1      Peg  PN      23:35.9  +30:28  12.1   5'32"      45  25-30

Key:
U2#: Chart number in Uranometria 2000.0 Deep Sky Atlas
Min.A: Minimal Aperture in cm (but also try smaller!)

Remarks

No.	Object	Remarks
1	NGC 7822	large, faint emission nebula; rated `eeF'; also look for E/R nebula Ced 214 (ass. with cluster Berkeley 59) 1 deg S
2	IC 59	faint emission/reflection nebulosity paired with IC 63 close to gamma Cas; requires clean optics; rated as `pF'
3	NGC 609	faint patch at low power; high power needed to resolve this rich cluster (also look for Trumpler 1 cluster 1 deg S)
4	IC 1795	brightest part of a complex nebulosity that includes IC 1805 and IC 1848; use a nebula filter
5	Maffei 1	heavily reddened galaxy; very faint; requires large aperture and black skies; nearby Maffei II probably invisible
6	NGC 1049	Class V globular in dward `Fornax system' Local Group galaxy 630,000 ly away, galaxy itself invisible ?
7	NGC 1275	Perseus A exploding galaxy; brightest member of Abell 426 gal. cl. 300 million ly away; see Webb vol. 5
8	NGC 1432/35	Pleiades nebulosity (also includes IC 349); brightest around Merope; requires transparent sky and clean optics
9	IC 342	large and diffuse face-on spiral; member of UMa-Cam cloud (Kemble's Cascade of stars also in this chart)
10	NGC 1499	California Nebula; very large and faint; use a wide-field telescope or big binoculars plus H-Beat filter
11	IC 405	Flaming Star Nebula; associated with runaway star AE Aurigae; see Burnham's Handbook page 285 (also look for IC 410)
12	HH 1	Herbig-Haro 1; best with no filter at 250x or more: bipolar jets from forming star; not plotted, 2.5' SW NGC 1999
13	IC 434/B 33	B 33 is the Horsehead Nebula, a dark nebula superimposed on a very faint emission nebula IC 434; use H-Beta filter in dark sky!
14	Sh 2-276	Barnard's Loop; SNR or interstellar bubble?; difficult to detect due to size; use filter and sweep with wide field
15	Abell 12	also called PK 198 -6.1; faint; not plotted on Uranometria but is on NW edge of mu Orionis; OIII filter required
16	IC 443	faint supernova remnant very close to eta Gem; use filter (also look for NGC 2174 and Sh 2-247 on this Chart)
17	J 900	Jonckheere 900; bright starlike planetary; plotted as PK 194 +2.1 in Uranometria; use OIII filter & high power
18	IC 2177	Eagle Nebula; large, faint; contains bright patches Gum 1 (-10d 28'), NGC 2327 (-11d 18') & Ced 90 (-12d 20')
19	PK 205+14.1	Medusa Nebula or Abell 21; much larger than plotted in Uranometria; impressive in large aperture with OIII filter
20	PK 164+31.1	extremely faint with two small components; use OIII filter; sometimes confused with nearby NGC 2474-75
21	Leo I	dwarf elliptical; satellite of Milky Way; very low surface brightness; 0.3deg N of Regulus!; requires clean optics
22	Abell 1367	cluster of some 30 or more galaxies within a 1deg field near 93 Leonis; see Webb Handbook Volume 5, page 139
23	NGC 3172	`Polarissma Borealis' - closest galaxy to the North Celestial Pole; small, faint and otherwise unremarkable
24	NGC 4236	very large, dim barred spiral; a diffuse glow (NGC 4395 on Chart 108 is a similar large diffuse face-on)
25	Mrk 205	Markarian 205; a faint star on SW edge of NGC 4319; plotted as a radio source; centre of the red-shift controversy
26	3C 273	at 2 to 3 billion light years away one of the most distant objects visible in amateur telescopes; magnitude variable
27	NGC 4676	`The Mice' or VV 224 - two classic interacting galaxies; very faint; double nature detectable at high power
28	Abell 1656	Coma Berenices galaxy cluster; very rich; 400 million light years away; brightest member NGC 4889; see Webb Volume 5
29	NGC 5053	faint and very loose globular 1deg SE of M53; requires large aperture to resolve; difficult in hazy skies; Class XI
30	NGC 5897	large, faint and loose globular; magnitude 10.9 in Atlas Coeli Catalogue; requires large aperture to resolve; Class XI
31	Abell 2065	Corona Borealis galaxy cluster; perhaps the most difficult object for amateur telescopes; 1.5 billion light years away; requires superb sky!
32	NGC 6027	Seyfert's Sextet (6027 A-F); compact group of 6 small and very faint galaxies; see Burnham's Handbook page 1793
33	B 72	Barnard's dark S-Nebula or `The Snake'; opacity of 6/6; 1.5 deg NNE of theta Ophiuchi; area rich in dark nebulas
34	NGC 6791	large, faint but very rich open cluster with 300 stars; a faint smear in smaller instruments; Type II 3 r
35	PK 064+05.1	Campbell's Hydrogen Star; very bright but very starlike; also catalogued as star BD +30 3639
36	M 1-92	Minkowski 92 or Footprint Nebula; bright, starlike reflection nebula; double at high magnification; associated star invisible
37	NGC 6822	Barnard's Galaxy; member of the Local Group; large but very low surface brightness; requires transparent skies
38	Palomar 11	brightest of 15 heavily reddened GCs found on Sky Survey; magnitude is misleading. 11 Terzan GCs more challenging
39	IC 4997	bright but starlike planetary; the challenge is to see the disk!; blink the field with and without a nebula filter
40	IC 1318	complex of nebulosity around gamma Cygni; multitude of patches in rich starfield; use a very wide field plus filter
41	PK 080-06.1	the `Egg Nebula'; a very small proto-planetary nebula; can owners of large telescopes detect polarization?
42	IC 1396	extremely large and diffuse area of emission nebulosity; use nebula filter and very wide field optics in dark sky
43	IC 5146	Cocoon Nebula; faint and diffuse; use H-Beta filter; at the end of the long filamentary dark nebula is Barnard 168
44	NGC 7317-20	Stephan's Quintet; 0.5 deg SSW of NGC 7331; easy to pick out 3 or 4 (also look for `companions' to 7331)
45	Jones 1	plotted as PK 104-29.1 (from Perek & Kohoutek catalogue) in Uranometria; large dim glow; OIII filter required

RASC's Finest NGC Objects list

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Hartmut Frommert
Christine Kronberg
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Last Modification: October 2, 2018