Question about something I saw in the sky.

[bravobulldog]

Let me begin by saying I am not an Astronomer or a Physicist. Just someone who has a passion for the two fields. We had a particularly cool clear night (this past Tuesday)here in Dallas, TX and I saw what looked like an extremely bright star. It was positioned just South of the constellation Orion. At first I thought it was the ISS, but I knew that was wrong. Seeing as I did not take my eye off of it for about 5 minutes. It would have moved out of sight by then. It was a very bright "crisp" white light. I was just wondering if anyone else saw this or knows of some celestial event that happened. Again, not a scientist here. Just curious.

Thank you

 

[Boris_Badenov]

This post would be better suited to Ask the Astronomer.

 

[jim48]

This post would be better suited to Ask the Astronomer.

Along with more information, please. How fast was it moving? Was it moving east west? North to south? Did it change color? How far above the horizon was it? Was anyone with you?

 

[yevaud]

Possibly Iridium Flare. There really wasn't anything that bright south of Orion that evening. Sirius A/B to the S/W was about it.

Moving this to Ask The Astronomer...

 

[bravobulldog]

Thank you for moving my post to the appropriate place. I'll pay more attention next time.

It was stationary or moving so slow I couldn't tell with just my eyes. It did not change color and didn't "twinkle" like any of the other stars in the sky. It was just bright point of light. If I remember right, I was looking West. From where I am in Dallas it looked to be between 40-50 degrees above the horizon, in close proximity to Sirius and Saiph(Orion). Its probably nothing, but I've never seen that there before. Or at least nothing that bright. And yes I did have someone with me, but they had less of a clue than I did. In any case I appreciate you guys taking the time to answer my question.

 

[yevaud]

Well, although you said it lasted a while, which is atypical for an Iridium Flare, I used my Starry Night for your location on that evening, and can't seem to locate any high magnitude stellar object present.

 

[docm]

In Eridanus, near Lepus and Orion....

http://www.universetoday.com/2009/11/27 ... lash-fire/

K. Itagaki of Yamagata, Japan was photographing the night sky in Eridanus two days ago when Hitoshi Yamaoka of Kyushu University noticed an anomaly – a possible classic nova event. Just how big a jump in amplitude did this star make? Try at least seven magnitudes within hours… and Joe Brimacombe was on it.

According to AAVSO Special Notice #181 released on November 25, 2009, there could be a possible nova in Eridanus. "Central Bureau Electronic Telegram No. 2050 (Daniel W. E. Green, Ed.) announces the discovery of a possible nova in Eridanus, as reported by Hitoshi Yamaoka, Kyushu University, by K. Itagaki, Yamagata, Japan, at magnitude 8.1 on images taken Nov. 25.536 UT. The object was confirmed by Itagaki on an image taken on Nov. 25.545.

According to CBET No. 2050, "Itagaki notes that there is a faint (mag about 15) object near this position on his archival patrol images. Yamaoka suggests that it might be the brightening of a 15th-mag blue star that is contained in many catalogs (USNO-B1.0 position end figures 54s.19, 42".9), noting that the amplitude of seven magnitudes is rather large for a dwarf nova, but somewhat small for a rapid classical nova. Yamaoka adds that the ASAS-3 system (Pojmanski 2002, Acta. Astron. 52, 397) also detected this object at the following V magnitudes: Nov. 10.236 UT, [14.0:; 19.241, 7.34; 22.179, 7.98; 24.269, 8.12." Finder charts for this object may be plotted using VSP by entering the coordinates into the form at the this URL.

This object has been assigned the VSX identifier VSX J044754.2-101043. An AUID will be assigned by the VSX moderators and will be added to the on-line version of this notice when it becomes available. Please report observations to the AAVSO International Database as N ERI 2009 or VSX J044754.2-101043."

Within 24 hours even more news came in via AAVSO Special Notice #182:

"This new variable object in Eridanus, originally called a possible nova in CBET 2050, is most likely a WZ Sge variable. It matches closely the coordinates of GSC1.2 05325-01837, listed in that catalog at 14.76 mag. At the peak outburst magnitude of 7.3, this is about 7.5 magnitudes amplitude, within the range of a galactic variable and lower than a typical nova. It appears to be fading and is about V=8.5 right now. However, WZ Sge cataclysmic variables have a complex light curve and the star may re-brighten. We are awaiting spectral
confirmation and possible GCVS naming, and will pass on that information as soon as possible.

As mentioned in Special Notice 181, the star has been entered as VSX J044754.2-101043 and now has an AUID of 000-BJR-847. You can submit observations to the AAVSO with either identifier. We have a preliminary sequence from Mati Morel, and have obtained BVRI imagery using the Bright Star Monitor at Astrokolkhoz Observatory
which we will use to construct a multiwavelength sequence tomorrow (November 27).

This is a good target for time series photometry, and at its current brightness, we highly recommend using filters. Larger telescopes should consider B or even U filters."

Congratulations to K. Itagaki on his latest discovery, to AAVSO for pinning it down and to Joe Brimacombe for his quick imaging of the phenomena!

 

[yevaud]

Bedamned. I was at Sky and Telescope on this question, and that didn't even leap out at me; in fact, I didn't even see it mentioned in reference to the night sky that evening.

 

[MeteorWayne]

Sorry I didn't have time to read the original question carefully, must have been busy.

What you saw was almost definately Sirius. It's the brightest star in the sky, and it's below Orion. At magnitude -1.5, the only other objects in the sky that are brighter right now are the Sun, Moon, and Jupiter (which is far away from Orion, currently among the dim stars of Capricorn)

It's certainly not the nova in Eridanus that docm mentioned, since that only reached mag +8, far too dim to be visible to the unaided eye.

 

[ianke]

I would think that Wayne is spot on on this. Sirrius raises a lot of questions this time of year at outreach events. If you are interested, there is a shareware program available out there that is easy, and quite educational. It is called Stellarium, and is used by a lot of amateur astronomers to get aquainted with the night sky. http://files.uberdownloads.com/apps/Stellarium/indexLeft.php

I recomend this program to many people who are interested in the night sky, and is great for showing where the more interesting objects are for beginner telescope users. Again, it is free, and it is easy to set up, and use. So, give it a "look, and see".