Maxim Usatov

Jeremy, I wish I had known you were there. Proper sights of scintillation! You should definitely join us next time.

Mal, I'm in London. A little too far for spontaneous driving at the moment, but who knows, maybe in the future?

I wish I'd seen this sooner, and I wish I was a little closer... Would be so glad to join. Really need more of these opportunities to camp and observe together. Max

I am up for it!

A high-speed filter, like the 6.5 nm f/2 Highspeed filter from Baader, is optimized to perform within the specified focal ratios range - f/3.4 to f/1.8 in this case. I don't know specifically how this done but imagine the bandpass is somehow blue-shifted (in concentric circles?) to compensate increasing angles of incidence with increasing distance off-axis, to match the light cone coming from a fast optical system. I don't think Antlia specifies an optimal range for their 3 nm filter, they just say "down to f/3," so this looks like a normal filter to me. I assume Antlia's filter is not "high-speed" per se, i.e. the bandpass is not variable with the off-axis distance. Maybe I am just imagining things, of course.

The 3 nm Antlia was placed in front of the EP. I have a little hard time understanding why it has to work specifically at f/3. Antlia's site says it works "down to f/3", so I understand anything slower than that should be fine. @Highburymark I'd be happy to give you a lift.

This is very cool!

Any place works for me. I'll be on a leave until Feb 21 but otherwise should be here the rest of the February and the whole March. Max

@Highburymark Would be very interested in a test and would be happy to bring the refractor. I'm based in West London. Perhaps, at a star party, or we can agree to drive out to a parking lot somewhere, weather permitting?

I'm in about the same position, but would not expect Chroma to be significantly different. We're talking about 10% transmission difference. But, of course, maybe there are other factors in play here. We need to get together somewhere and test this all out! I'm also wondering if I'm loosing anything with my telescope being a Chinese achromat and not a premium apo. Theoretically at low mags and narrowband observations there should be literally zero difference.

Decided to get out for an hour of two to a nearby car park under reasonably dark sky, about 1 hr driving from London. Conditions were very windy with temperature decreasing rapidly, so instead of carefully observing each object I decided to just give a quick tour over some of the targets. Setting: Date: 6 Feb 2022 6" TS f/5.9 Achromat on TS alt-azimuth mount PVS-14 with Gen3 Harder 2100 FOM tube, 2" APM Amici prism 67 mm TeleVue Plossl, giving 13X magnification and 3-degree field of view Filters: H-alpha Baader 7 nm and Antlia 3 nm, 642 nm IR Astronomik, DGM NPB Nebula filter Bortle class 4 site at White Hill Car Park near Kingsley, Hampshire (RG25 3EJ) SQM showed 20.34 - moon was 42% setting at 23:36 NGC 2024 the Flame Nebula IC 434 the Orion's Dagger and B33 the Horsehead Nebula Started observing at about 21:30 when the moon was still up and sky pretty bright, with the 7 nm H-alpha filter the Flame was remarkable, very bright object with tree-like dark lane structure, similar to a Stoyan's Interstellarum Deep Sky Guide sketch of 18" reflector view under dark sky. Horsehead was very remarkable and pretty bright. The smooth background emission of the Dagger was filling the field of view, the head's dark silhouette was detailed - almost photographic picture. Typically I could see a single dark lane in the center of the Flame and the hint of the structure in London's Bortle 8 sky, and I am generally unable to make out the head's shape, although I can definitely see a dark spot in the emission. Completely different story on a darker sky. Horsehead details are similar to 18" reflector Stoyan's sketch, and the Dagger is brighter and more extending through the 6" NV setup. Barnard's Loop The loop was pretty bright, very much extended, northern part appears to be brighter and exhibiting structure. Panning through it, its presence was obvious - an object completely invisible in this setup in Bortle 8. M42 and M43, NGC 1977 the Running Man Nebula Of course, always a magnificent sight, Huygens region extremely bright, photographic amount of details in extensions. The picture in 6" NV was closer to a photograph rather than any sketch I've seen, although I don't think I could see its very outer loop that almost touches Iota Orionis. NGC 1977 was considerably faint - just a glow around the three stars. No wonder I don't see it at all in the city. Switching to Antlia H-alpha 3 nm increased contrast and brought more details out on the Barnard's Loop, but for some reason it made little improvement on other objects above, which is somewhat opposite to what I concluded during the previous session, where 3 nm was strongly preferred for the views of the Gamma Cygni region. Someone has mentioned that the Antlia filter showed darkening towards the edge of the FOV. In my setup this effect was noticeable, but did not at all hurt the observations - something completely negligible. NGC 2237-9/46 the Rosette Nebula and the surroundings Magnificent object, considerably bright, fits great in the FOV, complex multi-layered shape with good contrast against the background, great amount of emission and dust details, appearing photographic in the 6" NV setup, definitely exceeding any sketches I've seen. Visually, the Rosette and the Horsehead/Flame nebulae appeared almost identical to what is shown on the photographs here: https://www.cloudyni...otography-r3149 Panning north from the Rosette, hydrogen clouds appeared everywhere in the FOV. Bracken's atlas names this Sh2-273, spanning about 3 degrees, but Interstellarum's atlas confines Sh2-273 to 1-degree nebulosity surrounding the NGC 2264 Christmas Tree Cluster. In 6" NV I could see hydrogen clouds extending all the way from the Rosette to the Christmas Tree and beyond - the whole area north to the Rosette is drained in hydrogen. I have marked the nebulosity surrounding NGC 2264 as faint, but that's only because the contrast is low, the nebulosity is superimposed on the hydrogen background. Panning south, Sh2-280 and Sh2-282 appear pretty bright and extended, both fitting the same FOV. Interstellarum atlas shows 282 as a considerably fainter object. Sh2-284 is pretty faint, lacking details. IC 2177 the Segaull Nebula, Sh2-292, Ced90 Pretty bright, very extended and curved shape. Sh2-292 round, pretty bright and distinctive. Sh2-297 (Ced 90) pretty brigth and distinct at the tip of the Seagull. Not much details seen, but interesting shapes. NGC 2359 the Thor's Helmet By the time I've got to it, SQM was 20.64, the Moon almost set but transparency wasn't great. The helmet was faint, appeared irregularly shaped through the 7 nm H-alpha filter, pretty small at 13X mangification. I wasn't sure if I saw the horns or just the brighter central part of it which appeared to be C-shaped. Wind and chill began to kick in at this point. The helmet was completely invisible unfiltered or through the DGM filter. With 3 nm H-alpha, there wasn't enough light to confirm any more details, and the 12 nm view was too bright lacking contrast. More magnification, better transparency and aperture would be desirable here. M51 the Whirlpool Galaxy, and other objects Unfiltered view was bright with spiral arms seen - definitely an improvement compared to NV through 90 mm refractor last year, but still very small through this setup at 13X magnification. At this point SQM showed 20.81 at zenith, but 20.48 in the direction of M51 which was elevated at about 45 degrees. Doubling power to 26X reduced contrast, with no additional details seen. 642 nm IR view helped darken the background a little and was the most preferred view at 13X without barlowing. DGM filter - no improvement over unfiltered. Interstellarum Deep Sky Guide shows more details seen in 14" reflector, so this galaxy wants aperture and good zenith placement. At this point I had to start to shut down as it became too windy and chill at 6 deg. C. Quick glimpse mode - M108 appeared a small edge-on spiral with bright stellar-like nucleus. M97 the Owl Nebula was very faint and round - I wonder if [OIII] filter would help here. M81 - the Bode's Galaxy and M82 - the Cigar Galaxy, both very bright. M81 didn't show much details but M82 three dark lanes visible. Something for other other time.

Tried the TS flattener at various spacings, didn't do much good for this particular scope. It's fine, really. I can tolerate that for the views I'm getting and the correct orientation with the prism.

Yeah, through the filter this 6" is really an apo! I wish the field was flat, but I think I'm fine with that instrument. Honestly, I haven't tried 3 nm in the city. I've tried 7 nm on Rosette with the 90 mm refractor and it was disappointing, and M42 was OK'ish, but the whole experience still a far cry from Gavin's pictures. Rural sky was a completely different story.

I've been an amateur astronomer for fifteen years, but I think only the last few nights I was priviledged to observe Milky Way's hydrogen regions in all their glory - thanks to NV. The setup was: 6" TS f/5.9 Achromat on TS alt-azimuth mount PVS-14 with Harder 2100 FOM tube 67 mm TeleVue Plossl, giving 13X magnification and 3-degree field of view H-alpha filters: Baader 7 nm and Antlia 3 nm APM Amici prism for right angle correct orientation view Interstellarum Deep Sky Atlas Bortle class 4 site at Wembury Point, England (SQM showed 20.60). Transparency 6/7. Initially started with the summer classics - M57, M13, etc, but once I tried the 3 nm filter on the Gamma Cygni region, I literally couldn't pull myself from roaming around this region surrounding Sadr all the three nights. It was mind-blowing. IC1318 and Crescent both photographic in appearance. Glowing, cury, textured emission in high contrast to dark patches and filaments. The dark triangle near LDN889 not only apparent in form, but exhibiting detailed structure. The eyepiece view was quite similar to this picture, if you squint your eye a little: https://bit.ly/3hJ4Ws4 The Crescent showed doubling front in the north and Y-shape in the center, mottled body, almost "electric," I guess, due to the scintillation. Visually was very similar to this picture: https://www.astrobac...-6888-Large.jpg Numerous DWB emission clouds and the Sh2-101 Tulip in Cygnus were bright - the whole region all appeared as pierced and surrounded by faint hydrogen emission, which was also easily apparent in the eyepiece. The extent of the nebula seen far exceeded what was shown in the Interstellarum atlas. NGC 7000 North America's Gulf was very detailed and at high contrast, with bright knots in Mexico and in the north. The IC5067 Pelican was bright, showing three protruding "fingers" and irregular shape. IC 5068, the Cygnus Arc, was bright and apparent, split into multiple irregular regions. IC5146 Cocoon was pretty bright, without much fine detail inside, and apparent central star. Looking at the Interstellarum Deep Sky Guide, I now see that on those emission nebulae I saw about similar level of detail to what Uwe Glahn saw in his 27" reflector. The wide field of the 6" showed the whole western portion of the Veil in its field, with irregular bright "claw" of IC1340. NGC 6974/9 with Pickering's Triangle, shown as visible from 12" aperture in the atlas, was pretty bright in the eyepiece. The eastern part had less detail, but its overall irregular shape easily seen. Ventured to IC1396 in Cepheus, it appeared very extended and pretty faint, I couldn't see much dark detail, although central round dark region was apparent. Sh2-132, Sh2-157 (bright), NGC7635 and NGC7538 all exhibited some degree of detail, but I am not too familiar with these objects, and left them for another occasion. I don't think I could see the bubble itself with certainty, but it's on a to-do list now. Going south, M27 was bright and pretty compact, compared to vast hydrogen clouds of Cygnus. I won't mention myriads of well-known and obscure star clusters along the way. I think I could see into great "depth" and could observe less well-known NGC clusters well. (Dolidze-Dzimselejsvili 11 is a really peculiar alignment of stars!) Roaming along the Galactic equator, I have never seen so many stars in the eyepeice in my life. I own mostly Cassegrain designs, but f/5.6 reduced to f/2.3 is something else. Carpets, laces of stars! I tried switching to "normal eyepiece", but literally couldn't see much, compared to the NV mode. The eye wasn't properly dark-adapted, and, to be honest, after the level of detail seen in NV it felt a little futile. I tried 7 nm H-alpha filter, but it showed significantly less detail than the 3 nm Antlia. From dark nebulae, Barnard's E (B142) in Aquila was apparent without filtering. Some dark nebulae, if overlaid on HII emission, were better seen with the hydrogen filter on. The last night before returning home I explored Sagittarius, literally bumping into M22 very low on the horizon while scanning manually, and it was a sight to behold! Definitely a top globular in my book now, replacing M13, along with Sadr surroundings being visually more engaging and richer than even the great Orion Nebula! And then... M8 Lagoon was almost a live photograph - silky-smooth whirlpool, bright and detailed flower-like center with stars, dark patches - it's difficult to describe! Looking at monochrome photographs of the Lagoon, I think visually what 6" showed that night comes quite close. I could spend the whole night on that object alone (or the Sadr!) but that was my first overview "mission" so I had to move on. The M20 Trifid was very bright, almost laser-etched on the sky background with irregular patches dividing it easily seen as pitch-black filaments. This photograph is similar to what was seen in the eyepiece (although yes, there was noise in the tube, and it wasn't that deep, so squint to get an idea): https://bit.ly/2TesrQo In that area further, M17, Omega, was very bright and high-contrast as well - I could see the Omega shape in it, so now I finally get why it's called that, and the center emission region was extremely bright and knotty. M16 Eagle appeared as an eagle with wings open, and although there was lots of texture, I couldn't see Pillars of Creation that night, but definitely worth a try at a higher elevation and with a barlow. Suddenly, my visual astronomy life is enriched with so many objects, exhibiting so many details. Comparing what I've seen with Uwe Glahn's and Ronald Stoyan's sketches in the Interstellarum Deep Sky Guide, on extended emission nebulae a 6" aperture with FOM 2100 NV under Bortle 4 sky shows more detail than unaided 27" reflector under very dark sky, and definitely exceeds 14". Could it get any better? On the way home, I had the opportunity to visit the Stonehenge! Max

Thank you, Jeremy!

Here is the recent light curve I have made of CG Draconis - an eclipsing dwarf nova star with a twist. The data was taken with 0.5 m CDK telescope in New Mexico during the night of May 16, following the call by J. Shears from the British Astronomical Association Variable Star Section. Being a dwarf nova, we are looking at a binary star system with the primary component being a white dwarf that accretes material from a main sequence secondary star: (illustration taken from NASA/CXC/M.Weiss.) As the mass falls onto the dwarf, it forms an accretion disk around it which is thermally unstable, producing periodic outbursts. The CG Dra system is very active. In addition to outbursts, CG Dra is an eclipsing binary. As the secondary component orbits the white dwarf and the extended accretion disk around it, it obscures them every period which results in an eclipse detectable with photometry (Shears et al. 2008). In brief, the CG Dra system can be characterized as following: - Outbursts approximately every 11 days. - Two types of outbursts: short and long. - Short outbursts endure for about 4 days, long for about 8 days. - Shallow eclipses every 4 hours or so, of about 0.16 magnitudes depth, 18 minutes duration. The system had only a few observations since 2008, so the goal was to check on the current behavior and see if there's anything new going on. I have observed the system remotely for three hours in the Johnson V filter, starting 06:02 and ending 09:04 UTC. The individual FITS frames were calibrated and processed with the MetroPSF photometry program I wrote. MetroPSF calibrates the images astrometrically, matches sources with AAVSO Photometric All Sky Survey (APASS) DR9 and VSX catalogs, identifies variables, conducts photometry and generates the reports and light curves pretty much automatically once all the settings are done correctly. In the light curve obtained we can see a ~ 0.2-magnitude dip beginning at about 59351.28 JD. This does not look like an actual eclipse. More likely it is just irregular modulations in the accretion disk - the 0.15 mag flickering this system is known of makes it a difficult target. Perhaps, the accretion disk is clumpy. The problems of CG Dra - why this dwarf nova is interesting: 1) Spectroscopic observations by Bruch et al. (1997) on a 3.5 m telescope at Calar Alto in Spain show that the secondary component is of K5 ± 2 spectral type. For main sequence stars there are known mass-type relationships that allow us to estimate the mass of a main sequence star if we know its type. If we know the mass we can estimate its period in a binary system. A type-mass relation taken from Schmidt-Kaler (1982) would imply a 6-hour period for CG Dra, inconsistent with 4-hour period observed by others. This can be explained by the secondary having higher density that a main sequence star, but this has never been observed in any dwarf nova before. 2) If CG Dra is a normal dwarf nova then the main sequence star of mass corresponding to the K5 ± 2 spectral type would not fit into its Roche lobe. The material begins to transfer when it overflows the Roche lobe, which appears to be impossible in this situation. Mass transfer and outbursts shouldn't be taking place! 3) Radial velocity measurements in the spectrum of the K5 V secondary are on the order of 30 times smaller than predicted for this system. It appears there is not enough wobble of the secondary in orbit due to the gravitational pull. Bruch et al. (1997) suggest the K5 spectrum may actually originate from a star that is not a part of CG Dra system. An optical coincidence? It would be interesting to capture an eclipse and follow this system. References: Bruch, A., Schimpke, T., Kochsiek, A. 1997, A&A, 325, 601 Schmidt-Kaler, T. 1982, in Landolt-Bornstein, 2b, ed. K. Schaifers, & H. H. Voig (Heidelberg: Springer) Shears, J., Boyd, D., Brady, S., Pickard, R. JBAA, 118, 6

Galaxies from central London? Really puzzled. I could barely see NGC 2903 in Leo which is quite bright, but transparency was not very good that night. I would be very curious to compare views through different telescopes/NV devices. Probably need to try pump up the magnification. Bright globular clusters are looking extremely good in NV indeed!

My congratulations! FC-100 is a fantastic scope - telescope for life, as someone said. May I recommend to look at Baader Morpheus 76 series of eyepieces. 15 years into this hobby, and 17.5 mm Morpheus is definitely among the most exciting EPs I've ever had. By the way, I have 24 mm Panoptic available for sale in London in very good condition, if you're looking into that direction. I decided I'll keep the Morpheus as it fits my f/5.6 Takahashi Sky 90 better, and sell the Panoptic. 24 mm Pan is definitely a legendary EP as well and should be a great fit to FC-100.

Thinking out loud, "standard glass" would be needed to perceive colors - carbon stars, double stars, open clusters and PNs, and some very bright emission nebulae. Also, NV tends to flatten the dynamic range, so estimating concentration class of globulars, or brightness range and even the degree of detachment of open clusters could be confusing. During this trip I had NV most of the time and used standard glass to complement the view. What other situations could be there - wide fields of view, perhaps? The 40-deg AFOV of PVS-14 doesn't bother me much, but going back to 76-deg Baader Morpheus produces wow effect, especially with Technicolor back on.

Dreyer's - here is the full list: http://www.alethis.net/astro/charts.html NV definitely "switches the lights on," but Dark Sky is still the king, along with his queen, Aperture.

Thanks, Marv. I am actually much slower - this was 2-3 hours per night, 4 nights. 🙂

Got a chance to take 90 mm refractor out with PVS-14 under Bortle 4 skies in South-East England. Initially planned for a bigger telescope, but literally didn't fit into my car with all the family belongings and whatnot, so had to change last minute to a grab-and-go rich field setup. Had clear sky four nights, high humidity though, and dew overcoming my heating, settling on the lens on a few occasions. It was quite cold, so had to limit myself to 2-3 hour sessions. This is in no chronological order, as brighter, spectacular objects were mixed with faint fuzzies description of which would be unremarkable. Leo Triplet – all three galaxies, considerably bright and small, fit nicely in the 3-degree field of view of a 40 mm Plossl at 13X magnification. M66 and M65 exhibited bright stellar cores, with a 12.3 magnitude star seen on the eastern side of M65. No dark lane visible in the fainter of NGC 3628 “Hamburger” due to poor image contrast, as transparency was only 4 out of 7, and the sky was bright, but the galaxy’s rectangular side-on shape was obvious. Albeit lacking much detail, the triplet at 35 Mly was a magnificent unforgettable sight. M51 and NGC 5195 pair was beautiful, considerably bright (cB) and small (S), with hints of spiral structure appearing as a concentric circle. Was happy to see this pair live, especially spending much time processing deep view of it and learning how to combine data from different telescopes - more than 10 years ago. I couldn’t see the bridge between the two galaxies at 13X with certainty, albeit returning to this location on two different nights, although on one night I thought I could see it. M81 and M82 were simply stunning, both bright (B), fitting in the same field of view at 13X. M82 showed knotting and asymmetric irregular brightness distribution and two, occasionally three, dust lanes running perpendicular to its body, popping in and out of view. The details were more prominent with a 2X barlow providing 26X magnification. I think I could see irregularities in M81 gradient, signifying hints of structure, but this could have been an illusion. M106 (cB, S) extended almost edge-on, had a bright core and a faint disk. In my log I have put ~ 30-degree inclination to the line of sight, which corresponds nicely to 27 degrees in the literature (Ann & Yu 1981). A hint of the dust lane on the south-eastern side. I should have probably used higher magnification to confirm this, but the cold weather and lakes of water forming on the atlas have dented my enthusiasm. Other galaxies demanded a darker background, warmer weather and more aperture to enjoy, so I just made a few brief remarks in my log and went on. I visited a number of galaxies from NGC, M105 (F), M63 (cB, ~ 30 degrees edge-on disk), M96 and M95 (cF), M108 (F, bM), M109 (vF, S, bM, stellar core). I couldn’t detect Leo I at all. The “Black Eye” M64 had unusually bright center in contrast to its faint disk, similar to M106, due to all the dust excess in it, I suppose. M101 appeared as faint, round, featureless glow (bM), with scintillating stellar core. From NGC, remarkable was the 2903 in Leo (cB, S, R, gbM, stellar core). I thought I could see the dust lane in 4631 “the Whale” (cF, S, edge-on), but was uncertain. 4565, “the Needle” (F, E, bM) showed no dust lane that night. Dark sky is very important even with NV. If the details are sunken in sky glow, there’s little that could be done to get them out, I guess. The AGC 1656 Coma Galaxy Cluster clearly demanded a bigger aperture. Absolutely spectacular Milky Way objects were those within about 30 kly – the right niche for a 90 mm f/5.6 refractor: M35 is one of my favorite small telescope objects, very bright and rich open cluster, brilliant even without NV. In my log I’ve recorded it as Trumpler class III3r. The much more distant NGC 2158 nearby appeared virtually as an irregular globular - a small roundish haze, unresolved at 13X, and completely unseen without NV that night. The Interstellarum Deep Sky Atlas lists both M35 and NGC 2158 as visible in 4-inch aperture, but the latter is actually a difficult object being 6 times further away. NGC 2158 partially resolved into stars with 685 nm IR-pass filter, which provided the best contrast on open clusters. M37 is another spectacular open cluster, detached with strong concentration, recorded it as class I2r. Without NV, a reddish 9-magnitude F8 star HD 39183 was prominent in its center at 29X magnification. M35 and M37 are objects that, I think, can deliver equal amounts of excitement with and without NV. M36 “the Frog” is quite a curiosity nearby, recorded as class II2r. I could see its irregular shape resembling T. rex footprint rather than a frog. I suggest it should be renamed the T. rex cluster! M38, bright open cluster, appeared as a four-petal shape with an underdensity of stars in the middle, recorded as class IV2r, as it wasn’t much detached from the field in the NV view. M3 globular cluster was splendid, very bright – literally photographic view. Amazing! Only the core region remained unresolved at 13X, however, when I switched to 26X, I could immediately resolve stars right in its center as well. It appeared even better at 38X, producing more resolved stars as I pumped up the mag. M13 appeared partially resolved, very bright, many individual stars seen - with curved “arms” emanating from the center. Just out of curiosity I’ve tried looking without NV and got a fuzzy ball with some individual brighter stars resolved – a very much different view. NV works wonders on star clusters. It was fairly low on the horizon for me, so M3 took the throne of being the most spectacular object this trip. M67 – one of my small telescope favorites as well – appeared bright, rich, fully resolved, class II2r. Other objects: M53 (cB, S, vmBM), a more distant globular cluster at ~58 kly, appeared significantly more concentrated than M3, with few stars resolved on the periphery. I couldn’t find NGC 5053 nearby. IC443, “the Jellyfish” supernova remnant (F, S) appeared as a cometary shape, well-defined edge on one side. 7 nm H-alpha filter provided the best view. Faint with 12 nm H-alpha filter, and not seen at all with IR-pass, DGM NPB filter or unfiltered. M97 “the Owl” planetary was more of a technical exercise. Not seen at all unfiltered in NV to my surprise, but considerably bright with 7 nm H-alpha filter, albeit still a featureless round blob in a sea of noise – no eyes seen. 12 nm H-alpha filter produced an image with less noise, but less contrast. With 642 nm IR-pass filter it was very, very faint, irregular glow. I remember seeing a much better image with C11 on a darker sky in Ukraine about 15 years ago, without NV, of course. The problem this trip was the lack of transparency. On galaxies unfiltered views were definitely the best. 685 nm was the winner for star clusters, and 7 nm H-alpha for HII emission nebulae. Whew, anybody still reading this? Max

You can safely ignore this. You may also want to edit the metropsf.py file and insert your own Astrometry.net API key, or use whatever key is currently in the source code.

Steve, when you select comparison catalog as "VizieR catalog" then you are basically telling you're using custom VizieR catalog to get comparison stars. You would need to enter VizieR catalog number in the text field there, e.g. II/306 for SDSS DR8 for example. The catalog you choose must also provide magnitudes in the filter name you have selected. Which one are you using? For V magnitudes you may want to select APASS DR9 instead of a custom catalog.

Beautiful host galaxy, supernova at V = 14.665 tonight.