Nigella Bryant

Yeah, me too, that's what's confusing me.

That could explain it. According to the field of view calculator I thought I'd have more room for maneuver.

Hi all, I bought a new Zwo Asi 178mm for my lunt 60mm. I'd used the field of view calculator b4 I purchased it and it calculated that I'd get a full disk image so I went ahead and bought it about 4 weeks ago. Only just able to use it. I couldn't get a full disk image, only partially. I then used a 0.5 reducer and too didn't provide a full disk image. I've previously been using a zwo120mm usb2 with a 0.5 reducer and this gave me a full image with the lunt. I'm pleased with the difference in resolution of the 178 but what if anything am I doing wrong. I quite savey with imaging equipment so any help would be appreciated. Thanks for reading.

Edward Guinan and other astronomers from Villanova University shared a brief update on Betelgeuse over the weekend, reporting it's now about one full magnitude fainter than it was in September. It still continues to behave uncharacteristically. BANG - in my opinion.

Should be brightening by now over the next few weeks but if it doesn't then it's unusual.

It seems that way, only the next month or so will tell.

Reported from the astronomers telegraph. We report further on the recent unusual dimming of the red supergiant Betelgeuse (alpha Ori) reported previously in ATel #13341 and ATel #13365. We continue to carry out V-band and Wing TiO and near-IR photometry of the star. Since our last report, Betelgeuse has continued to gradually decrease in brightness. Our most recent photometry secured on 17.25 UT and 18.20 UT January 2020 yields: V = +1.494 mag and 1.506 mag, respectively. This is more than ~0.2 mag fainter than previously reported in ATel #13365 on 22.25 UT Dec. 2019. However during the last week or so the decline in brightness of the star may be slowing. As reported by Brian Skiff of Lowell Observatory (priv. commun.) visual estimates of Betelgeuse are available as far back as about 180-years ago. Systematic visual measures of the star have been made by AAVSO observers since the 1920s. More precise photoelectric photometry began nearly 100 yrs ago but systematic (mostly unpublished) photometry of Betelgeuse commenced about 40-years ago at Villanova Observatory by Scott Wacker and Guinan. Betelgeuse is now nearly as faint as (the slightly variable) B2 star Bellatrix (V ~+1.62 mag). Bellatrix (gamma Ori) is about 5° west of Betelgeuse in the constellation Orion. The analysis of the calibrated Wing photometry (Wing 1992: JAAVSO 21, 42) returns measures of the temperature (via calibrated Wing TiO- and near-IR (B-C) color-indices) as well as estimates of bolometric magnitude (m-bol). The Wing intermediate band A-filter is used to measure the temperature-sensitive TiO 719-nm (gamma; 0, 0) molecular band. The B (750-nm) and C (1020.4-nm) filters are centered on relatively line-free stellar continuum regions. The C-band filter measures have been calibrated with K-M stars with bolometric magnitudes returning proxy measures of the apparent bolometric magnitude (m-bol) (see Wasatonic et al. 2015: PASP, 127, 1010). During the 25-years of V-band / Wing Near-IR photometry, Betelgeuse is currently the coolest and least luminous yet observed. Since September 2019, the star's temperature has decreased by ~100 K while its luminosity (inferred from the C-band/m-bol observations) has diminished by nearly 25%. At face value using R'/R = [(T'/T)^4 / L'/L]^0.5 (where R', T' and L' are the current values of stellar Radius, Temperature & Luminosity), this implies an increase of the star's radius of ~9%. However, as pointed out by others, the current fainting episode could also arise from expelled, cooling gas/dust partially obscuring the star. The recent changes defined by our V-band/Wing photometry seem best explained from changes in the envelop-outer convection atmosphere of this pulsating, unstable supergiant. If these recent light changes are due to an extra-large amplitude light pulse on the ~420-day period, then the next mid-light minimum is expected during late January/early February, 2020. If Betelgeuse continues to dim after that time then other possibilities will have to be considered. The unusual behavior of Betelgeuse should be closely watched.

Thanks Gina.

Hi James, don't know about using a dslr, I use a zwo camera with the sharpcap.

I've a neq6, I discarded using the polar scope and use sharpcap polar align and for £10 a year isn't even worth worrying about. It's so easy and done in a matter of minutes and spot on. Just a thought.

Thanks CedricTheBrave for the tip of painting the heater black.

Thanks for the info, looks like just what I need, I can run another cable 12v from the box if need be. Just ordered one, thanks.

Hi Dave, no box isn't sealed at cable end yet, didn't give it a thought about flocking the underside of the dome but it's only for night time use anyway. Misting was on the outside only however. Not sure what would work to get rid of the dome fogging over on the outside except what's used for eyepieces and secondary mirrors.

Hi Gina, only two usb cable's running from box. One for camera and the other for the fan.

Thanks Mars, I not proficient in wiring, would have to pick your brains, could that be made via USB cable connection too. Been looking at small USB heating pads as I've usb running from the box.

Hi Mars, after running the skycamera for a few hours there is fogging so I'm going to have to address that before I install it on the roof.

Undid the box and moved the camera slightly to try and miss the distortions and refocused and seems to be better.

I have a fan running and only just got it up and running so the answer is no Mars sure at the moment what will happen. Will let you know if I have issues.

Okay, tested this evening and there is some reflection, mark caused by the drill to the left of the image. Pleased that it's picking up quite a few stars and that the 10m run on the usb seems to be OK. Fan works too to keep things clear. So pleased with the way it's going but needs tweaks re: the dome. Might try and mount the camera outside the box under the dome to bring it closet to the top of the dome to see if this clears the distortions and marks I made drilling. Attacked a just a couple of quick single images taken with the allskybox. Pleased with the depth of image and sure it'll pick up meteors. I also think I need to tweak the focus slightly.

As I previously said, this last dimming cycle is quite unusual as the star is at record low brightness, and this dimming is significant enough to be seen by the naked eye. The latest data has the magnitude of the star at 1.5, which is 0.2 magnitudes dimmer than the previous known record of 1.3 magnitudes in 1927 and 1941. Rigel is 0.18 and about 100+ light years more distant than Betelgeuse, which is at 1.5 at the moment and much dimmer than Rigel.

Welcome to the forum and great first pic of the moon. It's now an expensive slippery slope into astro imaging, lol.

Yeah, I plan on trying it out first, hopefully it'll be OK. Some clear skies tomorrow evening so hopefully it'll be ready to test. Watch this space, lol.

A little bit more progress after life got in the way. Bolted and sealed dome and placed fan in box ready for camera installation tomorrow. Going to let the silicone dry before putting camera inside. Then I need to trail the USB cable's through the loft space.

Hi Stu, Severe Weather Europe post as of January 2020. You were bang on Stu, make a variable star observer of you yet, lol.