Object of the Week March 26th, 2023 - NGC3507 & NGC 3501

NGC 3507
UGC 6123
PGC33390

Galaxy

Leo

Class: SB(s)b

RA: 11h 03m 25.6s
DEC: +18° 08’ 08”

Mag: 11.9

Size: 4.6’x3.7’


Discovered in 1784 by William Herschel and his 18.7” f/14 speculum telescope, NGC 3507 is a beautiful barred spiral, face-on galaxy in the constellation Leo. NGC3507, although dim, does offer up a nice view for observers. In modern images, NGC3507 is a bit reminiscent of the Lost Galaxy of Virgo, NGC 4535.

Online reports indicate that NGC3507 has been observed in telescopes as small as 12”. Although faint, NGC 3507 is a moderately sized galaxy at approximately 3’ across. The galaxy appears to have a dual core as a 10^th magnitude star sits beside the actual galactic core itself. Only in the largest of telescopes will observers start to catch glimpses of NGC3507s ‘backward S’ arms.

Approximately 12.5’ southwest of NGC3507 is NGC 3501. NGC3501 is a difficult and faint edge-on spiral galaxy with its 12.9 magnitude and thin appearance that can give anyone a challenge.

Let me apologize for the brevity of this weeks OOTW. This week has been nothing short of busy and time was short. But, with that said, if you do get out anytime soon for galaxy season, be sure to give these two objects a go! I know I will!! I’d really like to read some reports before I do!

Always remember, give it a go and let us know!

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NGC-3507: With an 18" at 332x:"Almost missed it as just a star. Could see a glow around it. The FIELD GUIDE to URANOMETRIA indicates an 11th magnitude star superimposing over it."
NGC-3501: With a 20" at 313x:"Direct vision; best flat galaxy of the evening so far; some very slight bulge seen. PA~20-30 (27)."

Ngc 3507 galaxy in Leo ; magnitude: 11.9 ; size: 2.9' x 2.5' ; fairly dim with a bright central core, a 10th mag star right next to core. Discerning the arms took some time aand patience. I used a 8mm Ethos at 238x with my 14.5 Starstructure f/4.3Attachment 5085

Got a somewhat disappointed record of 3501 with my former 16-inch, even if it belongs to the RFGC. It shows as a thicker streak from 51x to the best magnification of 90x. No dark lane and no companion was visible.

3507 gave a much better picture in the 27-inch. It shows the nice embedded star, some star clumps and the brighter spirals.

sketch: 27", 293x, NELM 6m5+
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Three observations in my log for NGC3507, one for NGC3501. This pair is Holmberg 224 and KPG 263.

First observation for NGC3507 was in 2009, in my 12" SCT @ 191x / 26' under Dutch skies at a meager SQM 20.19:

A relatively large, round patch, no detail visible. Directly ENE of the middle is a mag. 12 star (TYC1433-01372-1), slightly farther to the SSW (approximately 1/10 FoV) is a mag. 11 star, twice that distance towards the NNE is a mag. 11.5 star.

Second time around was 2015 in the Alps, 14" SCT @ 168x / 29' and a pleasing 21.65 on the SQM. Session notes state: "Clear and a million, second night in a row that conditions are outstanding". As can be expected, the galaxy revealed a lot more detail:

Sharing the FoV with the galaxy NGC3501, almost 1/2 FoV to the SW: A round glow, gradually brighter in the middle. The nucleus is faintly visible with AV. ENE of the middle is a mag. 11 star (TYC1433-01372-1). With AV the outer halo of the galaxy is clearly visible and it is clear that the brighter core is slightly elongated east to west.

Third observation was only 2 years ago, from my light polluted backyard with the SQM meter pegging at a whopping 19.66. Again my 12" SCT @ 191x / 26. This time, I observed little more than the core and the superimposed star even appeared to be detached of (that what was visible of) the galaxy:

A faint, round glow directly west of a mag. 10 star (TYC1433-01372-1). This foreground star appears detached from the galaxy. With AV subtly and gradually brighter in the middle, sometimes the brighter core jumps into view but can not be held. No nucleus visible and no arms can be discerned.

My only observation for elongated NGC3501 was that superb night in the Alps:

Sharing the FoV with the galaxy NGC3507, almost 1/2 FoV to the NE: A clearly NE-SW extremely elongated streak, brighter in a core that is elongated in the same direction and that is slightly SW of the middle, no nucleus visible.

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Click here to download the guide for this week's OotW.