2019, April 1-30: Mars Moves Through Taurus

In the evening sky, Mars is moving through Taurus’ brighter star field. Follow the planet through a binocular as it passes between the Pleiades star cluster and the Hyades star cluster. The “V” of Taurus is nearly vertical this time of year. The stars of winter are making their final stand in the evening sky for the year, capped by an arc of stars – Procyon, Pollux, Castor and Capella.  The Gemini Twins stand high in the western sky with their arms around the other twin’s shoulders. Sirius is about 25° up in the southwest.  Watch it slowly begin to disappear into bright twilight.  Its last appearance in the evening sky occurs in mid-May.  The sun is in the sky for nearly 12.75 hours and the sky is dark, from the end of evening twilight to the beginning of morning twilight, for slightly over 8 hours.

In the notes that follow, the brightness of celestial objects is noted.  The lower the number the brighter the object.  The brightest stars have magnitudes that are rated 1 on the magnitude scale.  These can be seen from many bright areas.  As you move into suburban areas, magnitudes 2 and 3 are visible.  Fourth and fifth magnitude stars are visible from more rural areas.

Additionally, some stars have proper names as well as Greek letter designations, and sometimes numerical designations.

To determine the end of twilight in your area, find the local time in your area.  Add 100 minutes to your local sunset time.  By that time the sky is dark enough to find the constellations and Mars.

Look in the west about one-third of the way up in the sky, from horizon to overhead.  You’ll find Mars there along with the celestial backdrop of Taurus the Bull.

• April 1: At the end of evening twilight, Mars, about 28° up in the west, is 3.3° to the left of the Alcyone (η Tau, m = 2.8), the brightest of the Pleiades, and 2.6° below 37 Tauri (37 Tau, m = 4.4). For the next several evenings we have chosen stars in Taurus to reference with Mars.
• April 2: At the end of evening twilight, Mars is over 27° up in the west.  It is 3.5° to the upper left of Alcyone and 1.9° to the lower right of 37 Tauri.
• April 3:  At the end of evening twilight, Mars is 1.2° below 37 Tauri.
• April 4:  At the end of evening twilight, Mars is just below a virtual line that extends from Alcyone to Aldebaran (α Tau, m = 0.8).  The planet is 3.5° to the lower right of Omega Tauri (ω Tau, m = 4.9) and 0.6° below 37 Tauri.
• April 5: At the end of evening twilight, Mars is 0.3° to the left of 37 Tauri, above a virtual line from Alcyone to Aldebaran.
• April 6:  After the end of evening twilight, Mars is 0.8° to the upper left of 37 Tauri and 2.5° to the lower right of Omega Tauri.
• April 7: At the end of twilight, find Mars, 2.1° to the right of Omega Tauri.
• April 8:  At the end of evening twilight, the moon (3.7 days old, 14% illuminated) is about 6° to the lower left of Mars. The Red Planet is 4.5° to the lower right of Epsilon Tauri (ε Tau, m = 3.5), which compliments Aldebaran’s position in the head of Taurus at the top right point of the “V.”
• April 9: . At the end of evening twilight, Mars is 1.7° to the upper right of Omega Tauri and 4.2° to the right of Epsilon Tauri, just beneath a virtual line that extends from Aldebaran to Epsilon and to the right. The moon (4.7d, 22%) is not far away, 5.3° above Aldebaran.
• April 10: At the end of evening twilight, the moon (5.7d, 31%), 41° up in the west, is 3.5° to the upper left of Zeta Tauri (ζ Tau, m = 3.0), the southern horn of Taurus.  Mars, 24° up in the west, is 3.8° to the upper right of Epsilon Tauri, just above the imaginary line at that extends from Aldebaran through Epsilon.
• April 11: At the end of evening twilight, the moon (6.7d, 42%), over 50° up in the south-southwest, is nearly in the middle of Gemini, about 6° to the upper right of Gamma Geminorum (γ Gem, m = 1.9). Mars is 0.9° to the lower right of Upsilon Tauri (υ Tau, m = 4.2).
• April 12: At the end of evening twilight, the moon (7.7d, 53%), nearly 60° up in the southwest, is over 7° to the lower left of Pollux (β Gem, m = 1.2). Mars is 0.3° to the upper right of Kappa1 Tauri (κ1 Tau, m=4.2) and 0.3° below Upsilon Tauri.  It also passes 3.5° to the upper right of Epsilon Tauri.
• April 13: At the end of evening twilight Mars is 0.4° to the upper left of Upsilon Tauri.
• April 15: Mars is nearly midway between Upsilon Tauri and Tau Tauri (τ Tau, m = 4.3). Through a telescope, Mars is only 4” across, much smaller in apparent size than when it appeared at opposition last summer.
• April 16: At the end of evening twilight, the moon (11.7d, 92%), nearly 50° up in the southeast, is over 12° to the lower right of Denebola.  Mars (m = 1.6) is 1.3° to the right of Tau Tauri.
• April 17:  At the end of evening twilight, Mars continues its traverse of Taurus.  This evening it is 0.7° to the lower right of Tau Tauri.
• April 18: At the end of twilight, Mars is 0.3° to the upper right of Tau Tauri.
• April 19:  At the end of evening twilight Mars, marching through Taurus, is 0.6° above Tau Tauri.
• April 20: At the end of evening twilight, Mars is 1.3° above Tau Tauri and 4° to the lower right of Iota Tauri (m=4.6), next star to mark Mars’ course through the starry background.
• April 21:  At the end of evening twilight, Mars is 2° to the upper left of Tau Tauri and 3.5° to the lower right of Iota Tauri.
• April 22:  At the end of evening twilight, Mars is 3° to the lower right of Iota Tauri.
• April 23:At the end of evening twilight, Mars is 2.7° to the right of Iota Tauri and nearly 10° from Zeta Tauri, the southern horn of Taurus.
• April 24: At the end of evening twilight, Mars is 2.3° to the upper right of Iota Tauri and over 9° to the lower right of Zeta Tauri.  If you have a good western horizon and you can still view the “V” of Taurus, although it is low in the west-northwest, notice that Mars is above it for the next few evenings.  This evening Mars is over 9° to the upper right of Aldebaran.
• April 25: At the end of evening twilight, Mars, nearly 24° up in the west-northwest, is 2.2° to the upper right of Iota Tauri and over 8° to the lower right of Zeta Tauri.
• April 26: At the end of evening twilight, Mars is 2.3° to the upper right of Iota Tauri and 8° to the lower right of Zeta Tauri.
• April 27:  At the end of evening twilight, Mars is 2.6° to the upper right of Iota Tauri and over 7° to the lower right of Zeta Tauri.
• April 28: At the end of evening twilight, Mars is 2.7° to the upper right of Iota Tauri and about 7° to the lower right of Zeta Tauri.
• April 29:  At the end of evening twilight, Mars is 3.4° above Iota Tauri and over 6° to the lower right of Zeta Tauri.
• April 30:  At the end of evening twilight, Mars, nearly 16° up in the west-northwest, is 3.9° above Iota Tauri and about 6° to the lower right of Zeta Tauri.