Grazing Occultations during the rest of 2015 and during October 18 33rd Annual IOTA Meeting Las Vegas, Nevada Eberhard Riedel and David W. Dunham For 2015, see

A few remarks about my previous talks An open letter to Richard Nolthenius (& all IOTA observers): Congratulations on your successful recording of Fri. night’s occ’n by Oenone at Carrizo Plain! Yes, it’s a bummer that the Las Vegas region was hopelessly clouded out, but we knew days in advance that there would likely be problems there. I’m glad that you obtained an observation so that, at least to the accuracy of the radius of Oenone, we know where the path went. But it would have been so much better if you had also run a remote station 10 km to the north, and maybe another 10 km to the south. Two (or 3) separated chords are so much better for determining the size/shape of the asteroid, and obtaining a more accurate astrometric measurement of the asteroid relative to the star. A midi 80mm scope system that could have easily recorded the event (and others to 11 th mag. that occur reasonably often within a 150-mile travel radius) can cost less than $500, and for about $200 more, you could get a 120mm maxi that can reach the more frequent 12 th -mag. events. Maybe in your next equipment request to Cabrillo College, you might ask for that; the small scopes can be easily hidden and run unattended, as a few others and I often do, but when they fit your & their schedule, they could be attended by students as a great educational opportunity. Running more than one station takes more time & effort, but you’re used to challenges, taking long hikes & climbing mountains, I also enjoy those activities. Running 5 or more stations can be exhilarating, like an extreme sport; as I showed in my “down under” talk, 2 people working as a team can cover a whole occ’n path & the 1-sigma zones. I hope you & more other IOTA observers can take up the multi-station challenge, at least, start running one or two extra stations, maybe at first in the backyards of friends. Also, in & around Bakersfield, there are a couple of casual occultation observers not on IOTAoccultations who sometimes observe; it would have been good to notify them of the Oenone opportunity.

Alice Springs If you can afford it, I heartily recommend spending some time in central Australia (but it’s too hot there in the southern summer) Skies are completely clear about 75% of the time (almost as good as California’s Central Valley during the summer) And the southern sky is incredible! Sagittarius overhead with the brightest parts of the Milky Way from horizon to horizon. Alice Springs itself is light-polluted, but it’s not large (population less than 30,000) and there are no street lights on the highways between the much smaller communities (most just road houses) spaced about 80 km apart; 30 km outside of town give views better than any I’ve seen in the eastern US. I’m not an astrophotographer (just an occultation videographer); I’ll leave the taking of pretty sky pictures to others with much better equipped for that. Richard Williamson runs a store/shop (Comspec) in Alice Springs that sells telescopes, among many other things; he’s happy to help visiting astronomers Also, I hope someone in the US can really manufacture 10” suitcase telescopes (John Broughton’s design), they are compact and have 4 times the light-gathering power of maxi’s, giving good S/N for the frequent 11 th & 12 th -mag. occultations, I think they are the wave of the future for remote station deployments.

2015 Grazes

NO. YEAR MO DAY USNO SAOPPM D MAG %SNL L W.U.T. LONG LAT STAR NAME Nov 26 ZC A S alpha Tau(Aldebaran) Salt Lake City; Denver; Joplin, MO; Chattanooga; Myrtle Beach Dec 6 ZC T N theta Vir(Apami-Atsi) central Arizona; Socorro, NM; Lubbock; Waco; New Orleans (at cusp) (good for a multiple-station effort like we tried for 49 Leonis in Australia in June) The very best grazes this year (just 2 left)

NO. YEAR MO DAY USNO SAOPPM D MAG %SNL L W.U.T. LONG LAT STAR NAME Oct 29 ZC A N alpha Tau(Aldebaran) Nov 26 ZC A S alpha Tau(Aldebaran

# Date Star D Mag % Lim W.U.T. Long Lat 122 Oct 24 ZC S 2h39.5m e. Cuba; s.e. Bahamas 123 Oct Tauri K N s. Sask.; Manitoba From 2015 RASC Obs. Handbook

# Date Star D Mag % Lim W.U.T. Long Lat 128 Nov 4 xi Leonis V N Corpus Ch., TX; n. Florida 129 Nov 4 omicron Leo W S Coos Bay, OR (sunrise) 130 Nov 17 tau Cap I N Lake Winnipeg 144 Dec Aquarii S s.DAL,MEM,Hagerstwn,NYC,CapeCod 145 Dec 18 Z.C S s. Cuba, s.w. Bahamas

2016 Grazes Maybe the next IOTA meeting could be scheduled for one of the Aldebaran grazes; the one the morning of July 29 should be especially spectacular. This might be better than scheduling it with an asteroidal occultation. As we saw this year, it can be dangerous putting all your eggs in one basket for an asteroidal occultation; the Oenone occultation may have been better observed if the IOTA meeting had been held on another weekend [if, like the Oenone event, the path crosses a large part (length 500 miles or more) of the US, I’d prefer to have the freedom to go to where the weather is best for a good asteroidal occultation than be tied to a city with an IOTA meeting (without the meeting, it might have been worth the drive to Bakersfield to catch the event) ]. The same argument might be said for a good graze, but they are not as scientifically important, but could present a good educational/ public outreach opportunity in the host city (the July 29 th graze will be a rare naked-eye spectacle)

From 2016 RASC Obs. Handbook # Date Star D Mag % Lim W.U.T. Long Lat Location, remarks 2 Jan 8 Z.C N 12h27.0m e. St. Louis to Boone, NC 4 Jan 20 Aldebaran S LaPaz;Houston;BatonRouge;Savannah 10 Feb 2 eta Librae S Corners; Amarillo; Dallas; Miami 18 Feb Tauri V N s.BC; MSP; Detroit; Philadelphia 19 Feb 16 Aldebaran N Tacoma, Pasco, cen. Idaho Rho Sgr Feb. 6

# Date Star D Mag % Lim W.U.T. Long Lat Location, remarks 27 Mar 12 xi1 Ceti K S Eureka,CA; Provo,UT (bright side) 28 Mar 14 Z.C. 741 V N Rimouski,Quebec; n. Maine; n.N.S. 30 Mar 16 Z.C. 944 M N SFO, Fresno mg1=mg2=6.7, 0.5” 141d 41 Apr 3 18 Aquarii N Lebanon, TN; Myrtle Beach, SC 45 Apr 10 Aldebaran N BC, AB (day); Goose Bay, Labrador

# Date Star D Mag % Lim W.U.T. Long Lat Location, remarks 52 May 2 lambda Aqr S Montana, Dakotas, cen. Minnesota 54 May 8 gamma Tau K S Redding, Calif.; n. Reno, Nevada 60 Jun Leonis S Calgary-cen.Minn. 2015Jun22 AU star 69 Jul 13 kappa Vir S s. Oregon; n. of Boise, ID 78 Jul 29 Z.C. 677 X N Cincinatti,Pittsburg,Utica,Maine 79 Jul 29 Aldebaran N ElPaso,OK C,St.Louis,DTW(sunrise)

# Date Star D Mag % Lim W.U.T. Long Lat Location, remarks 89 Aug 25 Aldebaran N n. OR – NC, daytime 92 Sep 2 Jupiter N s.w. OR – Fla.Keys(day);s.Bahamas

# Date Star D Mag % Lim W.U.T. Long Lat Location, remarks 118 Oct 19 Aldebaran N LosAngeles,sLAS,Denver,MSP

# Date Star D Mag % Lim W.U.T. Long Lat Location, remarks 144 Dec 13 Aldebaran S cen. Mexico; Ft. Myers, FL 145 Dec 13 Aldebaran N British Columbia