Uranus’s Rare Close Encounter

The planet Uranus is spectacularly close to an almost identically bright star throughout late September.

Uranus is easy to see with binoculars or any telescope, and it's even visible to the unaided eye in clear skies far from city lights. Yet few people have knowingly seen this planet.

There are actually two separate problems: locating Uranus and being sure that you've found it. Uranus looks precisely like a star to the unaided eye and through binoculars too. A telescope at 100× does show Uranus as a minuscule dot. But it appears truly tiny, just one-eleventh the size of Jupiter, so it's still easy to mistake for a star.

But Uranus is easy to identify in late September, when it's very close to the star 44 Piscium. They're by far the brightest "double star" in their sector of the sky.

Uranus in late September 2012
Uranus is positioned very near 44 Piscium during late September 2012. Click above for a full-page finder chart in PDF format.
Sky & Telescope diagram
The pair is high enough to view easily by 10 p.m. daylight time. Look for the Great Square of Pegasus about halfway up the eastern sky; then look for the faint Circlet of Pisces to its lower right. Omega (ω) Piscium is lower left of the Circlet, and fainter Delta (δ) Piscium is lower left of Omega. Uranus and 44 Piscium form an isoceles triangle with Omega and Delta, as shown at right.

If your sky is too bright to see Omega and Delta Piscium without optical aid, you will need to star-hop down from the Great Square using binoculars or a finderscope using our detailed, full-page Uranus finder chart. This chart also gives a graphic representation of Uranus passing 44 Piscium on a day-by-day basis.

The two currently form a faint, close pair when viewed with the unaided eye under dark skies. From Friday through Monday they will be too close to resolve without optical aid, so they will appear to the unaided eye like a single star twice as bright as either component.

Binoculars separate the star from the planet, and they should also show their very different hues. Uranus has a distinctive color that's usually described as bluish or greenish, while 44 Piscium is distinctly yellow or orange by comparison.

At 100× or higher, a telescope should show that Uranus is a tiny extended disk or dot, while 44 Psc remains a spiky, pointlike star. Even if atmospheric conditions are poor, it should be clear that Uranus shimmers much less than the star.

This is a rare opportunity; it's almost unheard-of for a planet to be visible in the same high-power telescopic field of view with a similarly bright star. So make a point of viewing the pair any chance you get in the next week or two!

Separations for specific dates are listed below. These are all at 0h Universal Time, which falls on the evening of the preceding date in the time zones of the Americas. At closest approach around 12h UT (5 a.m. PDT) on September 23rd, Uranus will be 0.7′ south-southwest of 44 Piscium.

DateSeparation
September 1910.8′
September 208.4′
September 216.0′
September 223.7′
September 231.4′
September 241.4′
September 253.7′
September 266.1′
September 278.5′
September 2810.9′

To locate Uranus at other times, or to locate the planet Neptune, see our article on observing Uranus and Neptune in 2012.

7 thoughts on “Uranus’s Rare Close Encounter

  1. Tony Flanders

    44 Piscium is a yellow giant, G5III, roughly 100 times as luminous as the Sun, and 470+-30 light-years distant.

  2. Karsten Bomholt

    44 Piscium is a yellow giant star of spectral class G5III.It’s distance from Earth is about 500 light-years. The apparent magnitude is 5.77 and the absolutely magnitude is -0.53. It’s radial velocity is negative, which indicates that the star is approaching the solar system.

  3. Anthony Barreiro

    I’ve been enjoying watching Uranus approach 44 Piscium for the past month or so, saw them through binoculars from my urban back yard last night. It’s a bit surprising to see that Uranus, although so far away and orbiting the Sun so slowly, can be seen to move relative to the background stars from night to night. This year has been full of rare celestial events.

  4. Matthias Dopleb

    I have used the software GUIDE 9 to simulate the encounters over a longer time span: the apparent distance between Uranus and 44 Piscium is shrinking – from 55.1" in 1844 to a mere 15.1" in 2600, when Uranus will be west of 44 Piscium (currently south-southwest).
    Tomorrow observers on the southern hemisphere will see Uranus even a bit closer (by just half an arcsecond or so).

    22 Sep 1844 22:13 UT 55.1" (geocentr)
    23 Sep 1928 21:35 UT 48.9" (geocentr)

    23 Sep 2012 11:56 UT 40.8" (geocentr)
    23 Sep 2012 11:54 UT 41.3" (North)
    23 Sep 2012 11:58 UT 40.4" (South)

    24 Sep 2096 02:06 UT 37.0" (geocentr)
    25 Sep 2180 08:07 UT 33.9" (geocentr)
    27 Sep 2264 09:39 UT 32.8" (geocentr)
    29 Sep 2348 10:29 UT 29.0" (geocentr)
    01 Oct 2432 04:07 UT 23.3" (geocentr)
    03 Oct 2516 17:34 UT 17.3" (geocentr)
    06 Oct 2600 18:30 UT 15.1" (geocentr)
    08 Oct 2684 21:53 UT 16.1" (geocentr)
    12 Oct 2768 06:37 UT 18.5" (geocentr)

  5. Paul Cox

    I caught this image of Uranus and its satellites Oberon, Titania and Umbriel on the 24th Sept 2012 when Uranus was incredibly close to the star 44 Piscium: http://goo.gl/tDHJj

    I also created a time-lapse of Uranus approaching 44 Piscium over the last month: http://youtu.be/4fQcuyeWVaU

    We’re broadcasting a free public show tonight with live images of both the Harvest Moon and the ice-giant Uranus at opposition. It will be broadcast on the slooh.com homepage at 4 PM PDT / 7 PM EDT / 23:00 UTC.

    There are more details here: http://goo.gl/Hv9BV

  6. Anthony Barreiro

    Paul, the image and video are lovely, thanks for sharing them. What sort of telescope and camera did you use?

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