Artist’s impression of the structure of a sun-like star and red giant. (European Southern Observatory)
Among my favorite targets for visual astronomy are carbon stars. These objects are truly among the gems of the night sky, given their intense hues even for relatively dim examples. While most stars show little or no prominent color through the eyepiece, carbon stars shine forth with obvious colors ranging from pale pink to bright orange to deep, saturated red. During the Covid pandemic year of 2020-21, carbon stars became my observing obsession. As I started collecting examples, I built the list included on this page.
The astrophysics of carbon stars
Carbon stars get their name from the relatively high abundance of carbon in their atmospheres. Many (but not all) are evolved stars nearing the ends of their lives. "Classical" carbon stars are luminous red giants on the asymptotic giant branch. These are stars who have finished the longest phase of a star's life, which is when it fuses hydrogen to become helium in its core. The core then contracts and heats up until the temperature becomes high enough to ignite helium fusion. The star then burns helium in its core for about 100 million years, which leaves behind carbon as a fusion product.
The interiors of these stars are convective, and through a series of what are known as "dredge up" events, the carbon 'ash' from helium burning is mixed into the upper layers of the star. The result is an overabundance of carbon in the star's atmosphere relative to what were formerly more abundant elements like oxygen; in these stars, the free carbon mainly captures oxygen to form carbon monoxide (CO), which depletes free oxygen. In the relatively cool conditions in a red giant atmosphere, the carbon atoms condense into molecules that are good at absorbing and scattering short-wavelength (blue) light while letting long-wavelength (red) light through. Classical carbon stars there appear generally much more red than red giants that aren't dredging up carbon.
In addition to the classical carbon stars, there are both dwarf and supergiant carbon stars. It is thought that some of these stars, especially the dwarfs, are the products of mass transfer in binary systems, where classical carbon stars 'pollute' the atmospheres of their dwarf companions. And there are some oddballs in the mix, like carbon Cepheid variables (e.g., V553 Centauri), hydrogen-deficient carbon stars (e.g., HM Librae and RY Sagittarii), and SC/CS carbon stars that are thought to represent a transition between classical carbon stars and S-type stars, which are cool, late-type giants with approximately equal carbon and oxygen abundances.
Essentially all carbon stars are variable stars, with periods varying from a few days to hundreds of days. Their apparent colors depend on the phase of the variation; the deepest reds are generally found around minimum light. Lastly, all red giants suffer some degree of mass loss due to strong stellar winds, much of whose output is in the form of small carbon-rich grains resembling graphite. Carbon stars therefore produce much of the interstellar dust that helps subsequent generations of stars and planets to form.
For a very thorough, if slightly dated, review of carbon stars, see G. Wallerstein and G. Knapp, Carbon Stars, Annual Review of Astronomy and Astrophysics, Volume 36, 1998, pp. 369-434.
Observing carbon stars
There are dozens of relatively bright carbon stars that are easily within reach of small telescopes, even in relatively light-polluted places. That makes them attractive targets, especially for star parties and other public outreach events.
Because of the late stage of the stellar life cycle classical carbon stars represent, they tend to be found in the halo of our galaxy rather than in the disk. So, more often than not, we see them at high galactic latitude, which in the northern hemisphere makes them generally more prominent in the spring and fall. But there are many exceptions which, mainly due to geometry, makes some carbon stars appear close to or in the disk. For fainter examples, this can make identification tricky.
Estimating the brightness of carbon stars visually can be exceptionally tricky because of the way the human visual system adapts to operating at low light levels. Many amateur astronomers are familiar with the experience of 'dark adaptation', in which one can see fainter stars visually the longer one avoids bright sources of light. Similarly, the appearance of very faint objects can be improved by using 'averted vision' (i.e., looking off-center rather than directly toward the target). In both cases, the reasons have to do with a shift in the dominance of two types of photosensitive cells in the retina as one moves from a bright environment to a dark one, or vice versa. At high light levels, the dominant photosensitive cells sense color well across much of the visible spectrum. But at very low light levels, a different kind of cell takes over that offers no color discrimination but better sensitivity to faint light. Those cells are generally more sensitive to green and blue light than others colors.
The result, as the eye transitions from bright to dim light, is something called the Purkinje effect. As the cells sensitive to color become gradually less active, one's sensitivity to long-wavelength (i.e., red) light is lost first; this is why astronomers tend to use red flashlights to preserve their dark adaptation while being able to wayfind and read from books and charts at the telescope. So, when assessing the brightness of carbon stars under conditions of dark adaptation, observers tend to underestimate their magnitudes. It's actually more advantageous to estimate carbon star brightnesses when one isn't dark adapted, although that can make it tougher to see some carbon stars when they're at or near minimum light.
If, like me, you get hooked on observing these fascinating stars, consider signing up for the Astronomical League's Carbon Star Observing Program. Anyone who completes the program by observing all 100 stars on the AL's list will receive recognition for the achievement.
The list
While not an exhaustive catalog, the list of carbon stars below consists of 143 examples ranging in brightness from +4.5 (U Hydrae, at maximum light) to +18.0 (SU Tauri, at minimum light). The columns are as follows:
1: The common name for the star. The usual nomenclature for variable stars is preferred; otherwise, the name is rendered from a standard catalog designation (e.g., HD or SAO). Hyperlinks in each case lead to the SIMBAD Astronomical Database entry for the star.
2: Cutout image of the object from the Digitized Sky Survey. Where possible, these are pseudo-color composites using the red and blue DSS plates, substituting the blue plate for the green channel in order to emphasize just how red carbon stars often are. Where I can't get a good RGB composite using Skyview, I substitute a grayscale cutout from the DSS Red plate only. All images are 5 arcminutes on a side and have a plate scale of approximately one arcsecond per pixel.
3: Right ascension (epoch 2000.0).
4: Declination (epoch 2000.0).
5: The constellation in which the star appears.
6: Alternative catalog designation for the star. For most stars, this is taken from one of the following sources: HD, SAO, GSC or TYC.
7: Stellar spectral type from SIMBAD.
8: Maximum magnitude.
9: Minimum magnitude.
10: Period of variation in days.
11: Link to a finder chart from the American Association of Variable Star Observers (AAVSO). These finders are 30 arcminutes on a side with north up and east at left. They show stars as faint at 12th magnitude.
12: Sky & Telescope's Pocket Sky Atlas chart on which the object appears. If the star is not marked, its chart number appears in parentheses. (Note that stars may appear on more than one chart in the book; I note only one chart number on which the star's position seems most easily located.)
13: Uranometria 2000.0 chart of which the star appears. Same details apply as for column 12.
The list is also available for download as a CSV file here.
Sources
Stars appearing on this list are principally drawn from the Astronomical League's list of the 100 brightest carbon stars, supplemented with 28 additional stars on its "southern hemisphere" list and a few others around the sky. For more observing notes, see Bob King's article "Carbon Stars Will Make You See Red" (Sky & Telescope, 3 December 2014).
The astrophysics of carbon stars
Carbon stars get their name from the relatively high abundance of carbon in their atmospheres. Many (but not all) are evolved stars nearing the ends of their lives. "Classical" carbon stars are luminous red giants on the asymptotic giant branch. These are stars who have finished the longest phase of a star's life, which is when it fuses hydrogen to become helium in its core. The core then contracts and heats up until the temperature becomes high enough to ignite helium fusion. The star then burns helium in its core for about 100 million years, which leaves behind carbon as a fusion product.
The interiors of these stars are convective, and through a series of what are known as "dredge up" events, the carbon 'ash' from helium burning is mixed into the upper layers of the star. The result is an overabundance of carbon in the star's atmosphere relative to what were formerly more abundant elements like oxygen; in these stars, the free carbon mainly captures oxygen to form carbon monoxide (CO), which depletes free oxygen. In the relatively cool conditions in a red giant atmosphere, the carbon atoms condense into molecules that are good at absorbing and scattering short-wavelength (blue) light while letting long-wavelength (red) light through. Classical carbon stars there appear generally much more red than red giants that aren't dredging up carbon.
In addition to the classical carbon stars, there are both dwarf and supergiant carbon stars. It is thought that some of these stars, especially the dwarfs, are the products of mass transfer in binary systems, where classical carbon stars 'pollute' the atmospheres of their dwarf companions. And there are some oddballs in the mix, like carbon Cepheid variables (e.g., V553 Centauri), hydrogen-deficient carbon stars (e.g., HM Librae and RY Sagittarii), and SC/CS carbon stars that are thought to represent a transition between classical carbon stars and S-type stars, which are cool, late-type giants with approximately equal carbon and oxygen abundances.
Essentially all carbon stars are variable stars, with periods varying from a few days to hundreds of days. Their apparent colors depend on the phase of the variation; the deepest reds are generally found around minimum light. Lastly, all red giants suffer some degree of mass loss due to strong stellar winds, much of whose output is in the form of small carbon-rich grains resembling graphite. Carbon stars therefore produce much of the interstellar dust that helps subsequent generations of stars and planets to form.
For a very thorough, if slightly dated, review of carbon stars, see G. Wallerstein and G. Knapp, Carbon Stars, Annual Review of Astronomy and Astrophysics, Volume 36, 1998, pp. 369-434.
Observing carbon stars
There are dozens of relatively bright carbon stars that are easily within reach of small telescopes, even in relatively light-polluted places. That makes them attractive targets, especially for star parties and other public outreach events.
Because of the late stage of the stellar life cycle classical carbon stars represent, they tend to be found in the halo of our galaxy rather than in the disk. So, more often than not, we see them at high galactic latitude, which in the northern hemisphere makes them generally more prominent in the spring and fall. But there are many exceptions which, mainly due to geometry, makes some carbon stars appear close to or in the disk. For fainter examples, this can make identification tricky.
Estimating the brightness of carbon stars visually can be exceptionally tricky because of the way the human visual system adapts to operating at low light levels. Many amateur astronomers are familiar with the experience of 'dark adaptation', in which one can see fainter stars visually the longer one avoids bright sources of light. Similarly, the appearance of very faint objects can be improved by using 'averted vision' (i.e., looking off-center rather than directly toward the target). In both cases, the reasons have to do with a shift in the dominance of two types of photosensitive cells in the retina as one moves from a bright environment to a dark one, or vice versa. At high light levels, the dominant photosensitive cells sense color well across much of the visible spectrum. But at very low light levels, a different kind of cell takes over that offers no color discrimination but better sensitivity to faint light. Those cells are generally more sensitive to green and blue light than others colors.
The result, as the eye transitions from bright to dim light, is something called the Purkinje effect. As the cells sensitive to color become gradually less active, one's sensitivity to long-wavelength (i.e., red) light is lost first; this is why astronomers tend to use red flashlights to preserve their dark adaptation while being able to wayfind and read from books and charts at the telescope. So, when assessing the brightness of carbon stars under conditions of dark adaptation, observers tend to underestimate their magnitudes. It's actually more advantageous to estimate carbon star brightnesses when one isn't dark adapted, although that can make it tougher to see some carbon stars when they're at or near minimum light.
If, like me, you get hooked on observing these fascinating stars, consider signing up for the Astronomical League's Carbon Star Observing Program. Anyone who completes the program by observing all 100 stars on the AL's list will receive recognition for the achievement.
The list
While not an exhaustive catalog, the list of carbon stars below consists of 143 examples ranging in brightness from +4.5 (U Hydrae, at maximum light) to +18.0 (SU Tauri, at minimum light). The columns are as follows:
1: The common name for the star. The usual nomenclature for variable stars is preferred; otherwise, the name is rendered from a standard catalog designation (e.g., HD or SAO). Hyperlinks in each case lead to the SIMBAD Astronomical Database entry for the star.
2: Cutout image of the object from the Digitized Sky Survey. Where possible, these are pseudo-color composites using the red and blue DSS plates, substituting the blue plate for the green channel in order to emphasize just how red carbon stars often are. Where I can't get a good RGB composite using Skyview, I substitute a grayscale cutout from the DSS Red plate only. All images are 5 arcminutes on a side and have a plate scale of approximately one arcsecond per pixel.
3: Right ascension (epoch 2000.0).
4: Declination (epoch 2000.0).
5: The constellation in which the star appears.
6: Alternative catalog designation for the star. For most stars, this is taken from one of the following sources: HD, SAO, GSC or TYC.
7: Stellar spectral type from SIMBAD.
8: Maximum magnitude.
9: Minimum magnitude.
10: Period of variation in days.
11: Link to a finder chart from the American Association of Variable Star Observers (AAVSO). These finders are 30 arcminutes on a side with north up and east at left. They show stars as faint at 12th magnitude.
12: Sky & Telescope's Pocket Sky Atlas chart on which the object appears. If the star is not marked, its chart number appears in parentheses. (Note that stars may appear on more than one chart in the book; I note only one chart number on which the star's position seems most easily located.)
13: Uranometria 2000.0 chart of which the star appears. Same details apply as for column 12.
The list is also available for download as a CSV file here.
Sources
Stars appearing on this list are principally drawn from the Astronomical League's list of the 100 brightest carbon stars, supplemented with 28 additional stars on its "southern hemisphere" list and a few others around the sky. For more observing notes, see Bob King's article "Carbon Stars Will Make You See Red" (Sky & Telescope, 3 December 2014).
| A | B | C | D | E | F | G | H | I | J | K | L | M | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Name | DSS image | RA (J2000.0) | DEC (J2000.0) | Con | Cat | SIMBAD SpType | Max Mag | Min Mag | P (d) | Finder | S&T | Uran. |
2 | WZ Cas |  | 00h 01m 15s | +60° 21′ 19″ | Cas | HD 224855 | C-N7III | 6.9 | 11.0 | 186 | PNG | 1 | 35 |
3 | SU And |  | 00h 04m 36s | +43° 33′ 04″ | And | HD 225217 | C-N5 | 8.0 | 8.5 | Irr | PNG | (3) | 59 |
4 | HD 26 |  | 00h 05m 22s | +08° 47′ 16″ | Psc | SAO 109003 | C-H1.5 | 8.2 | 8.3 | -- | PNG | (74) | (170) |
5 | ST Cas |  | 00h 17m 32s | +50° 17′ 14″ | Cas | HD 1306 | C-N5 | 11.6 | 12.4 | -- | PNG | 3 | 171 |
6 | VX And |  | 00h 19m 54s | +44° 42′ 33″ | And | HD 1546 | C-J4.5 | 7.8 | 9.3 | 369 | PNG | (3) | (59) |
7 | NQ Cas |  | 00h 24m 35s | +54° 17′ 17″ | Cas | HD 1994 | C-J4.5 | 10.6 | 11.5 | -- | PNG | (3) | (35) |
8 | AQ And |  | 00h 27m 31s | +35 °35′ 14″ | And | HD 2342 | C-N5+ | 6.9 | 8.6 | 346 | PNG | (3) | 90 |
9 | HD 5223 |  | 00h 54m 13s | +24° 04′ 01″ | And | NSV 15196 | C-H2IIIb | 8.3 | 8.7 | 755 | PNG | (5) | (127) |
10 | W Cas |  | 00h 54m 53s | +58° 33′ 49″ | Cas | HD 5235 | C9,1e | 7.8 | 12.5 | 406 | PNG | (3) | 36 |
11 | Z Psc |  | 01h 16m 05s | +25° 46′ 09″ | Psc | HD 7561 | C-N5 | 6.5 | 7.9 | 144 | PNG | 5 | 127 |
12 | R Scl |  | 01h 26m 58s | –32° 32′ 35″ | Scl | SAO 193122 | C-N5+ | 5.8 | 8.8 | 370 | PNG | 9 | 352 |
13 | WW Cas |  | 01h 33m 33s | +57° 45′ 05″ | Cas | HIP 7260 | C5,5 | 9.1 | 11.7 | -- | PNG | (1) | 37 |
14 | V Ari |  | 02h 15m 00s | +12° 14′ 23″ | Ari | HD 13826 | C-H3.5 | 8.3 | 10.8 | 77 | PNG | (4) | 174 |
15 | R For |  | 02h 29m 15s | –26° 05′ 55″ | For | GSC 6433:295 | C4,3e | 7.5 | 13.0 | 386 | PNG | 6 | 310 |
16 | HD 16115 |  | 02h 35m 06s | –09° 26′ 34″ | Cet | SAO 129989 | C-H3II | 8.2 | 8.5 | -- | PNG | (6) | (265) |
17 | UY And |  | 02h 38m 23s | +39° 10′ 09″ | And | HD 16326 | C5,4 | 7.4 | 12.3 | -- | PNG | (2) | 62 |
18 | V623 Cas |  | 03h 11m 25s | +57° 54′ 11″ | Cas | HD 19557 | C-J4 | 7.3 | 8.1 | -- | PNG | (13) | 38 |
19 | Y Per |  | 03h 27m 42s | +44° 10′ 36″ | Per | HD 21280 | C5,3e_Ba5 | 8.1 | 11.3 | 252 | PNG | (13) | 63 |
20 | V466 Per |  | 03h 41m 29s | +51° 30′ 11″ | Per | HD 232820 | C5,5_MS4 | 8.4 | 8.9 | -- | PNG | (13) | (39) |
21 | U Cam |  | 03h 41m 48s | +62° 38′ 54″ | Cam | HD 22611 | C-N5 | 6.9 | 7.6 | 400 | PNG | 11 | (18) |
22 | AC Per |  | 03h 45m 03s | +44° 46′ 52″ | Per | TYC 2875-2430-1 | C-N5 | 9.0 | 9.6 | -- | PNG | (13) | (64) |
23 | SAO 216512 |  | 03h 50m 05s | –43° 32′ 03″ | Eri | GSC 7576:1023 | C-H4:IIIa | 8.3 | 8.6 | -- | PNG | (19) | (391) |
24 | UV Cam |  | 04h 05m 53s | +61° 47′ 39″ | Cam | HD 25408 | C-J4 | 7.5 | 8.1 | 294 | PNG | 11 | 18 |
25 | XX Cam |  | 04h 08m 39s | +53° 21′ 39″ | Cam | HD 25878 | F8I | 7.1 | 10.0 | -- | PNG | 13 | 39 |
26 | T Cae |  | 04h 47m 18s | –36° 12′ 33″ | Cae | SAO 195295 | C-N4IV | 7.5 | 7.6 | 158 | PNG | 18 | 357 |
27 | ST Cam |  | 04h 51m 13s | +68° 10′ 07″ | Cam | HD 30243 | C-N5 | 6.7 | 8.4 | 300 | PNG | 11 | 19 |
28 | TT Tau |  | 04h 51m 31s | +28° 31′ 36″ | Tau | HD 30755 | C-N5+ | 7.7 | 10.0 | 167 | PNG | (12) | 96 |
29 | V346 Aur |  | 04h 52m 35s | +38° 30′ 20″ | Aur | HD 280188 | C8,1J | 9.3 | 9.8 | 365 | PNG | (12) | 96 |
30 | R Lep |  | 04h 59m 36s | –14° 48′ 22″ | Lep | HD 31996 | C7,6e | 5.5 | 11.7 | 427 | PNG | 16 | 269 |
31 | EL Aur |  | 05h 03m 23s | +50° 37′ 58″ | Aur | HD 32088 | C-N5- | 8.5 | 8.7 | Irr | PNG | (12) | (40) |
32 | W Ori |  | 05h 05m 23s | +01° 10′ 39″ | Ori | HD 32736 | C-N5 | 5.8 | 10.0 | 212 | PNG | 14 | 225 |
33 | TX Aur |  | 05h 09m 05s | +39° 00′ 08″ | Aur | HD 33016 | C-N4.5 | 8.5 | 9.2 | Irr | PNG | (12) | 65 |
34 | SY Eri |  | 05h 09m 48s | –05° 30′ 55″ | Eri | HD 33404 | C-N5 | 8.3 | 10.0 | 96 | PNG | (16) | (225) |
35 | UV Aur |  | 05h 21m 48s | +32° 30′ 43″ | Aur | HD 34842 | C8,1Je | 7.4 | 10.6 | 394 | PNG | 12 | (97) |
36 | S Aur |  | 05h 27m 07s | +34° 08′ 59″ | Aur | HD 35556 | C-N5+ | 8.2 | 13.3 | 590 | PNG | (12) | 97 |
37 | RT Ori |  | 05h 33m 13s | +07° 09′ 12″ | Ori | HD 36602 | C-N5 | 8 | 8.9 | 321 | PNG | (14) | 180 |
38 | SZ Lep |  | 05h 35m 47s | –25° 44′ 18″ | Lep | SAO 170582 | C-N3.5III | 7.4 | 7.9 | 83 | PNG | 16 | (315) |
39 | S Cam |  | 05h 41m 02s | +68° 47′ 55″ | Cam | HD 36972 | C-N6- | 7.7 | 11.6 | 327 | PNG | (11) | 20 |
40 | W Pic |  | 05h 43m 13s | –46° 27′ 13″ | Pic | SAO 217489 | C-J5 | 7 | 7.8 | 331 | PNG | 18 | (393) |
41 | TU Tau |  | 05h 45m 13s | +24° 25′ 12″ | Tau | HD 38218 | C-N4+ | 5.9 | 9.2 | 190 | PNG | 14 | 136 |
42 | Y Tau |  | 05h 45m 39s | +20° 41′ 42″ | Tau | HD 38307 | C-N5- | 6.5 | 9.2 | 242 | PNG | 14 | 136 |
43 | FU Aur |  | 05h 48m 08s | +30° 37′ 51″ | Aur | HD 38572 | C-N6 | 8.3 | 8.5 | -- | PNG | 12 | (98) |
44 | SU Tau |  | 05h 49m 04s | +19° 04′ 22″ | Tau | HD 247925 | C1,0_Hd_CH0 | 9.1 | 18.0 | 45 | PNG | (14) | 136 |
45 | TU Gem |  | 06h 10m 53s | +26° 00′ 53″ | Gem | HD 42272 | C-N5+ | 7.4 | 8.4 | 230 | PNG | 14 | 137 |
46 | GK Ori |  | 06h 17m 42s | +08° 31′ 11″ | Ori | HIP 29896 | C-N5- | 9.5 | 11.0 | 236 | PNG | (14) | 182 |
47 | FU Mon |  | 06h 22m 23s | +03° 25′ 27″ | Mon | HD 44544 | S6.5/7.5 | 8.5 | 9.8 | 310 | PNG | (14) | (227) |
48 | IV CMa |  | 06h 23m 39s | –27° 03′ 56″ | CMa | GSC 6514:102 | C-N5- | 8.2 | 8.8 | 423 | PNG | (29) | (317) |
49 | V Aur |  | 06h 24m 02s | +47° 42′ 23″ | Aur | HD 44388 | C6,2e | 8.5 | 13.0 | 333 | PNG | (23) | 67 |
50 | BL Ori |  | 06h 25m 28s | +14° 43′ 19″ | Ori | HD 44984 | C-N5- | 6 | 7.0 | 154 | PNG | 25 | 182 |
51 | RV Aur |  | 06h 34m 45s | +42° 30′ 13″ | Aur | HD 46321 | C5,3 | 9.9 | 10.4 | 229 | PNG | (23) | (67) |
52 | UU Aur |  | 06h 36m 32s | +38° 26′ 43″ | Aur | HD 46687 | C-N5- | 5.1 | 7.0 | 235 | PNG | 23 | 99 |
53 | VW Gem |  | 06h 42m 08s | +31° 27′ 17″ | Gem | HD 47883 | C5,4_Ba5 | 8.1 | 8.5 | Irr | PNG | (23) | 99 |
54 | GY Mon |  | 06h 53m 11s | –04° 34′ 34″ | Mon | HD 50436 | C-N5+ | 8.1 | 9.0 | Irr | PNG | 27 | 228 |
55 | NP Pup |  | 06h 54m 26s | –42° 21′ 56″ | Pup | SAO 218296 | C-N4.5 | 6.3 | 6.5 | 107 | PNG | (29) | 395 |
56 | RV Mon |  | 06h 58m 21s | +06° 10′ 01″ | Mon | HD 51620 | C4,5 | 7 | 8.9 | 121 | PNG | 25 | 183 |
57 | V614 Mon |  | 07h 01m 01s | –03° 15′ 09″ | Mon | HD 52432 | C-J3.5 | 7 | 7.4 | 60 | PNG | 27 | 228 |
58 | RY Mon |  | 07h 06m 56s | –07° 33′ 26″ | Mon | TYC 5381-403-1 | C-N5 | 7.5 | 9.2 | 456 | PNG | (27) | 273 |
59 | W CMa |  | 07h 08m 03s | –11° 55′ 23″ | CMa | HD 54361 | C-N5 | 6.4 | 7.9 | Irr | PNG | 27 | 273 |
60 | R CMi |  | 07h 08m 42s | +10° 01′ 26″ | CMi | HD 54300 | SC4-7/10e | 7.3 | 11.6 | 338 | PNG | 25 | 183 |
61 | BM Gem |  | 07h 20m 59s | +24° 59′ 58″ | Gem | TYC 1913-1170-1 | C-J5- | 8.3 | 9.2 | 286 | PNG | (25) | (139) |
62 | RU Cam |  | 07h 21m 44s | +69° 40′ 14″ | Cam | HD 56167 | C0,1_CH4 | 8.1 | 9.8 | 22 | PNG | (21) | 21 |
63 | NQ Gem |  | 07h 31m 54s | +24° 30′ 12″ | Gem | HD 59643 | C6,2_CH3 | 7.4 | 8.0 | 58 | PNG | 25 | 139 |
64 | V406 Pup |  | 07h 56m 20s | –49° 58′ 55″ | Pup | SAO 219177 | C-N4.5 | 7.4 | 8.2 | Irr | PNG | 28 | (396) |
65 | RT Pup |  | 08h 05m 19s | –38° 46′ 36″ | Pup | SAO 198783 | C-N5.5IIIa | 8 | 9.2 | Irr | PNG | (28) | (362) |
66 | RU Pup |  | 08h 07m 29s | –22° 54′ 45″ | Pup | HD 67507 | C-N5III | 8.1 | 11.1 | 425 | PNG | (26) | 320 |
67 | R Pyx |  | 08h 45m 30s | –28° 12′ 02″ | Pyx | SAO 176430 | C | 7.8 | 9.6 | 365 | PNG | (26) | 321 |
68 | UZ Pyx |  | 08h 46m 36s | –29° 43′ 41″ | Pyx | SAO 176458 | C-J4 | 7 | 7.5 | 160 | PNG | 26 | (363) |
69 | X Cnc |  | 08h 55m 22s | +17° 13′ 52″ | Cnc | HD 76221 | C-N4.5 | 5.6 | 7.5 | 195 | PNG | 24 | 142 |
70 | T Cnc |  | 08h 56m 40s | +19° 30′ 56″ | Cnc | TYC 1397-648-1 | C-N5 | 7.6 | 10.5 | 482 | PNG | 24 | 142 |
71 | RT UMa |  | 09h 18m 24s | +51° 24′ 08″ | UMa | TYC 3431-229-1 | C4+,4 | 8.6 | 9.6 | -- | PNG | (33) | 44 |
72 | Y Hya |  | 09h 51m 03s | –23° 01′ 02″ | Hya | HD 85495 | C-N4.5III | 6.5 | 9.0 | 154 | PNG | 37 | 323 |
73 | V Vel |  | 09h 55m 26s | –41° 35′ 12″ | Vel | SAO 221606 | F8II | 6.7 | 7.2 | 4 | PNG | (39) | (398) |
74 | AB Ant |  | 10h 11m 53s | –35° 19′ 29″ | Ant | SAO 201156 | C-N4.5III | 6.6 | 7.1 | Irr | PNG | 39 | (365) |
75 | XZ Vel |  | 10h 17m 27s | –50° 05′ 49″ | Vel | CD-49 5125 | C-N:5 | 8 | 8.5 | 281 | PNG | (39) | (399) |
76 | U Ant |  | 10h 35m 12s | –39° 33′ 45″ | Ant | SAO 201533 | C-N3 | 5.5 | 6.8 | Irr | PNG | 38 | 399 |
77 | U Hya |  | 10h 37m 33s | –13° 23′ 04″ | Hya | HD 92055 | C-N5 | 4.5 | 6.2 | 389 | PNG | 36 | 280 |
78 | SAO 222254 |  | 10h 40m 49s | –48° 01′ 30″ | Vel | GSC 8201:1209 | K0_Ba5 | 7 | 7.2 | ? | PNG | (38) | (399) |
79 | VY UMa |  | 10h 45m 04s | +67° 24′ 40″ | Uma | HD 92839 | C-N5 | 5.9 | 7.0 | 120 | PNG | 31 | 24 |
80 | V Hya |  | 10h 51m 37s | –21° 15′ 00″ | Hya | SAO 179278 | C-N:6 | 6.5 | 12.0 | 531 | PNG | 36 | 325 |
81 | TV Cen |  | 12h 14m 31s | –51° 31′ 57″ | Cen | GSC 8242:1963 | C | 7.8 | 8.5 | 146 | PNG | (49) | (428) |
82 | S Cen |  | 12h 24m 33s | –49° 26′ 24″ | Cen | SAO 223414 | C-R4 | 6.5 | 8.0 | 65 | PNG | (49) | 402 |
83 | SS Vir |  | 12h 25m 14s | +00° 46′ 10″ | Vir | HD 108105 | C-N4.5 | 6 | 9.6 | 361 | PNG | 47 | 238 |
84 | Y CVn |  | 12h 45m 07s | +45° 26′ 24″ | CVn | HD 110914 | C-N5 | 4.8 | 6.4 | 268 | PNG | 43 | 75 |
85 | RU Vir |  | 12h 47m 19s | +04° 08′ 41″ | Vir | HD 111166 | C8,1e | 8.1 | 14.2 | 434 | PNG | (45) | 239 |
86 | DY Cru |  | 12h 47m 24s | –59° 41′ 41″ | Cru | TYC 8659-1394-1 | C-N5.5 | 8 | 12 | Irr | PNG | (50) | (429) |
87 | RY Dra |  | 12h 56m 25s | +65° 59′ 39″ | Dra | HD 112559 | C-N3III | 6 | 8.0 | 200 | PNG | 41 | 26 |
88 | TT CVn |  | 12h 59m 22s | +37° 49′ 04″ | CVn | HD 112869 | C-H4- | 8 | 8.6 | 105 | PNG | (43) | (108) |
89 | HD 113801 |  | 13h 06m 24s | –20° 03′ 31″ | Vir | SAO 157721 | C-R3III | 8.5 | 8.5 | -- | PNG | (47) | (330) |
90 | UY Cen |  | 13h 16m 31s | –44° 42′ 15″ | Cen | SAO 224021 | S6/8 | 6.9 | 8.4 | 180 | PNG | 49 | 403 |
91 | Z Lup |  | 14h 35m 51s | –43° 22′ 02″ | Lup | GSC 7818:129 | C4,3 | 7.5 | 8.3 | 288 | PNG | (48) | 404 |
92 | V553 Cen |  | 14h 46m 33s | –32° 10′ 15″ | Cen | SAO 205930 | G5I/IIIpCH | 8.2 | 8.8 | 2 | PNG | (48) | 372 |
93 | HM Lib |  | 15h 27m 48s | –25° 10′ 10″ | Lib | SAO 183485 | C-Hd1Ib | 7.4 | 7.6 | Irr | PNG | 57 | 334 |
94 | R CrB |  | 15h 48m 34s | +28° 09′ 24″ | CrB | HD 141527 | G0Iep | 5.7 | 15.2 | Irr | PNG | 53 | 155 |
95 | V CrB |  | 15h 49m 31s | +39° 34′ 17″ | CrB | HD 141826 | C6,2e_MS3 | 6.9 | 12.6 | 358 | PNG | 53 | 79 |
96 | RR Her |  | 16h 04m 13s | +50° 29′ 56″ | Her | HD 144578 | SC5.5-C71e | 7.8 | 12.5 | 240 | PNG | (53) | 51 |
97 | V Oph |  | 16h 26m 43s | –12° 25′ 35″ | Oph | HD 148182 | C-N:4 | 7.3 | 11.6 | 297 | PNG | 56 | 291 |
98 | SU Sco |  | 16h 40m 38s | –32° 22′ 48″ | Sco | SAO 207911 | C-N5- | 7 | 9.4 | 414 | PNG | 56 | 375 |
99 | SAO 46574 |  | 17h 13m 31s | +42° 06′ 22″ | Her | HD 156074 | C-R2III | 7.3 | 7.7 | -- | PNG | (52) | (81) |
100 | TW Oph |  | 17h 29m 43s | –19° 28′ 22″ | Oph | HD 158377 | C-N5 | 7 | 9.0 | 185 | PNG | (56) | 338 |
101 | TT Sco |  | 17h 40m 30s | –41° 37′ 49″ | Sco | SAO 228265 | C4,4 | 8 | 9.0 | 138 | PNG | (58) | 408 |
102 | SZ Sgr |  | 17h 44m 56s | –18° 39′ 26″ | Sgr | HD 161208 | C-N5.5 | 8.2 | 9.2 | 73 | PNG | (67) | (338) |
103 | SX Sco |  | 17h 47m 28s | –35° 42′ 04″ | Sco | SAO 209256 | C-N5 | 7 | 9.5 | Irr | PNG | (58) | 377 |
104 | T Dra |  | 17h 56m 23s | +58° 13′ 06″ | Dra | HIP 87820 | C6,2e | 7.2 | 13.5 | 422 | PNG | 52 | 53 |
105 | FO Ser |  | 18h 19m 21s | –15° 36′ 46″ | Ser | HD 168227 | C-J4+ | 8.5 | 8.7 | Irr | PNG | (67) | 294 |
106 | AC Her |  | 18h 30m 16s | +21° 52′ 00″ | Her | HD 170756 | F4Ibp | 6.9 | 9.0 | 75 | PNG | 65 | 160 |
107 | T Lyr |  | 18h 32m 20s | +36° 59′ 55″ | Lyr | TYC 2636-1142-1 | C-J4:p | 7.5 | 9.3 | Irr | PNG | 63 | 117 |
108 | HK Lyr |  | 18h 42m 50s | +36° 57′ 30″ | Lyr | HD 173291 | C-N5 | 7.8 | 9.6 | 186 | PNG | 63 | 117 |
109 | RV Sct |  | 18h 47m 25s | –13° 12′ 48″ | Sct | HD 173138 | C-R4+ | 8.7 | 9.1 | -- | PNG | (67) | (295) |
110 | S Sct |  | 18h 58m 20s | –07° 54′ 27″ | Sct | HD 174325 | C-N5 | 6.3 | 9.0 | 150 | PNG | 67 | 295 |
111 | UV Aql |  | 18h 58m 32s | +14° 21′ 49″ | Aql | HD 176200 | C5,3 | 8 | 9.6 | 386 | PNG | 65 | 206 |
112 | V Aql |  | 19h 04m 24s | –05° 41′ 05″ | Aql | HD 177336 | C-N5 | 6.6 | 8.4 | 407 | PNG | 67 | 251 |
113 | RY Sgr |  | 19h 16m 32s | –33° 31′ 20″ | Sgr | SAO 211117 | Cpec | 5.8 | 14.0 | 38 | PNG | 66 | 379 |
114 | V1942 Sgr |  | 19h 19m 09s | –15° 54′ 30″ | Sgr | HD 180953 | C-N5+ | 6.7 | 7.0 | 121 | PNG | 66 | 296 |
115 | U Lyr |  | 19h 20m 09s | +37° 52′ 36″ | Lyr | TYC 3134-1708-1 | C4,5e | 8.3 | 13.5 | 452 | PNG | (63) | 118 |
116 | UX Dra |  | 19h 21m 35s | +76° 33′ 34″ | Dra | HD 183556 | C-N5 | 5.9 | 7.1 | 175 | PNG | 61 | 13 |
117 | NSV 11960 |  | 19h 23m 10s | –10° 42′ 11″ | Aql | HD 182040 | C-Hd2II | 7 | 7.1 | 29 | PNG | 66 | 296 |
118 | AW Cyg |  | 19h 28m 47s | +46° 02′ 38″ | Cyg | TYC 3543-2275-1 | C4,5 | 7.1 | 8.5 | 206 | PNG | (63) | (83) |
119 | AQ Sgr |  | 19h 34m 18s | –16° 22′ 27″ | Sgr | HD 184283 | C-N5 | 6.6 | 8.5 | 200 | PNG | 66 | 297 |
120 | TT Cyg |  | 19h 40m 57s | +32° 37′ 05″ | Cyg | HD 186047 | C-N5- | 7 | 9.1 | 118 | PNG | (62) | 119 |
121 | AX Cyg |  | 19h 57m 12s | +44° 15′ 40″ | Cyg | HD 189256 | C-N5- | 7.9 | 8.8 | 361 | PNG | 62 | (84) |
122 | V1469 Aql |  | 20h 01m 03s | +09° 30′ 51″ | Aql | HD 189711 | C4,3_CH3 | 8.4 | 8.7 | 98 | PNG | (64) | (207) |
123 | BF Sge |  | 20h 02m 23s | +21° 05′ 24″ | Sge | HD 190048 | C2,4 | 8.5 | 10.0 | 177 | PNG | (64) | (162) |
124 | X Sge |  | 20h 05m 05s | +20° 38′ 51″ | Sge | HD 190606 | C6,4 | 7 | 9.7 | 196 | PNG | 64 | (163) |
125 | SV Cyg |  | 20h 09m 30s | +47° 52′ 17″ | Cyg | HD 191738 | C7,4e | 8.5 | 8.7 | 196 | PNG | (62) | (84) |
126 | RY Cyg |  | 20h 10m 23s | +35° 56′ 50″ | Cyg | HD 191783 | C5,4 | 8.5 | 10.3 | Irr | PNG | (62) | 119 |
127 | RS Cyg |  | 20h 13m 23s | +38° 43′ 44″ | Cyg | HD 192443 | C-N5.5 | 6.5 | 9.5 | 417 | PNG | 62 | 119 |
128 | RT Cap |  | 20h 17m 06s | –21° 19′ 04″ | Cap | HD 192737 | C6,4 | 7 | 8.1 | 422 | PNG | 66 | 343 |
129 | WX Cyg |  | 20h 18m 33s | +37° 26′ 59″ | Cyg | HD 193368 | C-J6 | 8.8 | 13.2 | 410 | PNG | (62) | 119 |
130 | U Cyg |  | 20h 19m 36s | +47° 53′ 39″ | Cyg | HD 193680 | C9,2e | 5.9 | 12.1 | 463 | PNG | 62 | 84 |
131 | V Cyg |  | 20h 41m 18s | +48° 08′ 28″ | Cyg | TYC 3578-3282-1 | C7,4eJ | 7.7 | 13.9 | 421 | PNG | 62 | 85 |
132 | CY Cyg |  | 20h 46m 50s | +46° 03′ 06″ | Cyg | HD 198164 | SC2_Zr0 | 7.9 | 8.4 | -- | PNG | (62) | (85) |
133 |  | 20h 48m 37s | +17° 50′ 24″ | Del | HD 198269 | C-H3IV | 7.9 | 8.1 | -- | PNG | (64) | (164) | |
134 | NSV 13571 |  | 21h 09m 59s | +26° 36′ 55″ | Vul | HD 201626 | C-H2IV | 8.1 | 8.2 | -- | PNG | (75) | (165) |
135 | T Ind |  | 21h 20m 09s | –45° 01′ 18″ | Ind | SAO 230635 | C7,2 | 6 | 8.5 | 272 | PNG | 68 | 413 |
136 | S Cep |  | 21h 35m 13s | +78° 37′ 28″ | Cep | HD 206362 | C7,3e | 7.4 | 12.9 | 484 | PNG | 71 | 14 |
137 | V460 Cyg |  | 21h 42m 01s | +35° 30′ 36″ | Cyg | HD 206570 | C-N5 | 5.6 | 7.0 | 180 | PNG | 73 | 122 |
138 | RV Cyg |  | 21h 43m 16s | +38° 01′ 02″ | Cyg | HD 206750 | C-N5 | 7.1 | 9.3 | 263 | PNG | 73 | 122 |
139 | RX Peg |  | 21h 56m 22s | +22° 51′ 43″ | Peg | HD208526 | C-J4.5 | 7.7 | 9.5 | 629 | PNG | (75) | 166 |
140 | RZ Peg |  | 22h 05m 52s | +33° 30′ 24″ | Peg | HD 209890 | SC5-9/9-e | 7.6 | 13.6 | 437 | PNG | 73 | 122 |
141 | RU Aqr |  | 23h 24m 24s | –17° 19′ 08″ | Aqu | HD 220515 | M4/5III | 8.5 | 10.1 | 119 | PNG | (76) | 349 |
142 | ST And |  | 23h 38m 45s | +35° 46′ 21″ | And | HD 222241 | C5,4e_MS3 | 7.7 | 11.8 | 327 | PNG | (72) | 124 |
143 | TX Psc |  | 23h 46m 23s | +03° 29′ 12″ | Psc | HD 223075 | C-N6 | 4.8 | 5.2 | Irr | PNG | 74 | 215 |
144 | SAO 128396 |  | 23h 49m 05s | +06° 22′ 57″ | Psc | HD 223393 | C-R3III | 8.5 | 8.8 | -- | PNG | (74) | (170) |