Sky & Telescope - March 2021 - 64

Planetary Nebulae

TYC 1993-1812-1
97

TYC 1993-1282-1
113

Star magnitudes

ρ

14h 00m

13h 30m
M3

2
3
4
5
6
7

13h 00m

12h 30m +30°

γ

β
+25°

LoTr 5

BOÖTES
Arcturus

α

M64

COMA
BERENICES

η
τ

M53

+20°
M85

α

M100

M88 M99
+15°
M91

WS FINAL CHALLENGE Located in Coma Berenices, LoTr 5 is
some 6.8° east of the cluster that represents Queen Berenice's locks,
Collinder 256. It's neatly placed within a triangle formed by three 10thand 11th-magnitude stars. The nebula's central white dwarf is an easy
catch and shows up well in images such as this one. But only a handful
of observers have bagged the planetary itself. Have you?

TYC 1993-1790-1
113

IN Comae (BD +26 2405), a known binary with a period a
little more than 7 years, making it one of the longest-period
binaries associated with planetary nebulae. It likely consists
of a G-type subgiant with a very hot subdwarf companion.
The central star is rather easily seen. The nebula, on the other
hand, is quite another story. I wonder how many observers
have conﬁdently sighted it?
When we view planetary nebulae, we are witnessing a
process whereby low- to intermediate-mass stars enrich the
interstellar medium with many of the elements essential to
life on Earth. Carbon, nitrogen, oxygen, neon, and sulfur are
all present in signiﬁcant quantities. It seems serendipitous
that these remarkable objects glow their brightest at the very

wavelengths that we humans are best disposed to detect. We
might also consider ourselves fortunate that so many of these
nebulae are visible to us at all - they bloom for so relatively
short a time. In my ﬁrst article for Sky & Telescope (June
2010), I likened them to celestial ﬂowers. They also foretell
the eventual fate of our Sun and remind us of our place in the
cycle of creation.

 Contributing Editor TED FORTE's favorite targets are
planetary nebulae. He's the coordinator of the Astronomical
League's Planetary Nebula Observing Program and would
enjoy hearing from observers who wish to share their observations. He can be reached at tedforte511@gmail.com.

Springtime Planetaries
Name / Nickname

Const.

Filter

Mag(v)

Mag(*)

Size

RA

Dec.

NGC 3242

Ghost of Jupiter

Hya

[O III / UHC]

7.7

13.3

64″

10h

NGC 3132

Eight-Burst Nebula

Vel

[O III]

9.2

10.0

88″

10h 07.0m

-40° 26′

Owl Nebula

UMa

[O III]

9.9

16.0

170″

11h 14.8m

+55° 01′

33.1m

+82° 34′

M97
IC 3568
NGC 2818
J 900

24.8m

-18° 39′

Lemon Slice

Cam

[O III / UHC]

10.6

13.4

10″

12h

-

Pyx

O III / UHC

11.6

19.5

93″

09h 16.0m

-36° 38′

14″

06h

26.0m

+17° 47′

24.5m

-18° 47′
-16° 09′

PN G194.2+02.5

Gem

[O III / UHC]

11.7

17.8

NGC 4361

-

Crv

-

10.9

13.2

126″

12h

NGC 2610

-

Hya

UHC

12.7

15.9

42″

08h 33.4m

JnEr 1

PN G164.8+31.1

Lyn

O III / UHC

12.1

16.8

380″

07h 57.9m

+52° 25′

K 2-2

PN G204.1+04.7

Mon

O III

-

15.0

415″

06h 52.5m

+09° 58′

PuWe 1

PN G158.9+17.8

Lyn

UHC

-

15.3

1200″

06h 19.6m

+55° 37′

525″

12h

+25° 53′

LoTr 5

PN G339.9+88.4

Com

O III

-

14.9

55.6m

Brackets around filters indicate they aren't necessary but improve the view. Angular sizes are from recent catalogs. Visually, an object's size is often smaller than the
cataloged value and varies according to the aperture and magnification of the viewing instrument. Right ascension and declination are for equinox 2000.0.

64

MARCH 2 021 * SK Y & TELESCOPE

STEFA N BINNE WIES / JOSEF PÖPSEL / CA PELL A OBSERVATORY

Object
Sky & Telescope - March 2021

Table of Contents for the Digital Edition of Sky & Telescope - March 2021
