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Eyepiece Views #1
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THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
Tel. 617-354-0484 Fax 617-354-0665
http://www.aavso.org
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E Y E P I E C E V I E W S
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July, 2001 Vol 1 No 1
Table of Contents
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1. Introduction to the Eyepiece Views
2. Visual Observing Program
3. Novalike variable in Scorpius
4. Comments on LPVs by J.A.M
5. Comments on interesting stars by Mike Simonsen
6. Recently Published Charts
7. Mira's Companion
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1. INTRODUCTION TO THE EYEPIECE VIEWS
This is the first issue of a new AAVSO electronic publication for
visual variable star observers, prepared by AAVSO Technical Staff
Gamze Menali and Aaron Price with contributions from our avid visual
observer Mike Simonsen. Our goal with this publication is to support
our observers' visual observing programs with lists of new targets, new
observing program ideas, and information that is both interesting and
helpful. I will add comments on stars, mostly long period variables
(LPVs) that need more observations and other news from time to time.
EYEPIECE VIEWS will be published bimonthly and as needed. It will
be distributed primarily via e-mail and will be archived on our
website. To receive future issues of EYEPIECE VIEWS send a message to
majordomo@aavso.org with "subscribe eyepieceviews" in the body of the
e-mail.
As this is the first issue of this publication we anticipate some
tweaking and minor changes over the first few issues. We welcome suggestions,
comments, feedback, and contributions from observers as we strive to make
this publication your observing aid. Please send your comments to
eyepieceviews@aavso.org.
Thank you and we hope you find this new publication both useful and
enjoyable!
Good observing!
Janet Mattei (JAM)
Director
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2. VISUAL OBSERVING PROGRAM
Visual observations of variable stars make up the largest
component of the AAVSO International Database now containing over 10
million observations on approximately 4,000 variable stars. These
stars are primarily large-amplitude (visual range greater than one
magnitude). The types of variables include; pulsating (Mira,
semiregular, RV Tauri, Cepheids), eruptive or cataclysmic (dwarf nova,
nova, recurrent nova, novalike, supernova, symbiotic), R Coronae
Borealis, nebular (T Tauri, flare), irregular, and suspected
variables. The observations on these stars are sent directly to AAVSO
Headquarters. We also have several hundred eclipsing binary and RR
Lyrae stars in the visual observing program and their observaitons are
sent directly to the chairmen of these special committees.
Due to the wide range of periods and magnitudes of variation from
type to type, some stars need more frequent observations and require more
specific reporting of their observing time than others. Below is a table
that gives the suggested frequency of observations together with the digit
of the Julian day their observations should be reported at to the AAVSO.
TYPE OF STAR OBSERVING FREQUENCY REPORT JD TO
Cepheids Every clear night 4 decimal places
Cataclysmic var. Every clear night 4 decimal places
Mira variables Once per week 1 decimal place
Semiregular Once per week 1 decimal place
RV Tauri stars Once per week 1 decimal place
Symbiotic stars* Once per week 1 decimal place
R CrB* stars During maximum once
per week 1 decimal place
R CrB stars During fadings every
clear night 4 decimal places
Irregular variables Once per week 1 decimal place
Suspected variables Every clear night 4 decimal places
Flare stars Continuously for 10 to 15
minutes for rare
outbursts. 4 decimal places
Eclipsing binaries Every 10 minutes
during eclipse 4 decimal places
RR Lyrae stars Every 10 minutes 4 decimal places
Note: Symbiotic stars and R CrB stars may experience possible
small-magnitude, short-period variability. If you are interested in
looking for this, then observations should be made every clear night
and reported to 4 decimal places.
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3. 1750-32 V1178 Sco - A NOVALIKE VARIABLE IN SCORPIUS
Katsumi Haseda, Toyohasi, Aichi, Japan discovered a novalike
variable in Scorpius using 10-cm f/4 twin patrol cameras and
T-Max 400 film (IAUC 7647 and AAVSO Alert Notice 285). The object
was at magnitude 10.5 on June 15. The object has been slowly fading,
with fluctuations since then.
Here are some recent observations of 1750-32 V1178 SCO
1750-32 V1178 SCO JUN 25.1493 11.9: (E. VAN BALLEGOIJ,
ORANJESTAD, ARUBA)
1750-32 V1178 SCO JUN 25.2673 11.6 (K. YOUNG, WRIGHTWOOD, CA)
1750-32 V1178 SCO JUN 25.3020 11.5 (J. YOUNG, WRIGHTWOOD, CA)
1750-32 V1178 SCO JUN 25.9788 12.27 CCDV (W. LILLER, RENACA, VINA
DEL MAR, CHILE)
1750-32 V1178 SCO JUN 26.0095 12.33 CCDV (W. LILLER, RENACA, VINA
DEL MAR, CHILE)
1750-32 V1178 SCO JUN 26.1085 12.23 CCDV (W. LILLER, RENACA, VINA
DEL MAR, CHILE)
1750-32 V1178 SCO JUN 26.1458 12.1: (E. VAN BALLEGOIJ,
ORANJESTAD, ARUBA)
1750-32 V1178 SCO JUN 26.1916 12.22 CCDV (W. LILLER, RENACA, VINA
DEL MAR, CHILE)
1750-32 V1178 SCO JUN 26.9767 11.70 CCDV (W. LILLER, RENACA, VINA
DEL MAR, CHILE)
1750-32 V1178 SCO JUN 27.0071 11.70 CCDV (W. LILLER, RENACA, VINA
DEL MAR, CHILE)
1750-32 V1178 SCO JUN 27.1061 11.85 CCDV (W. LILLER, RENACA, VINA
DEL MAR, CHILE)
1750-32 V1178 SCO JUN 27.1639 11.6 CCDR (S. O'CONNOR, QUEBEC,
CANADA)
1750-32 V1178 SCO JUN 27.1674 12.4 CCDV (S. O'CONNOR, QUEBEC,
CANADA)
1750-32 V1178 SCO JUN 27.1842 11.74 CCDV (W. LILLER, RENACA, VINA
DEL MAR, CHILE)
1750-32 V1178 SCO JUN 27.2604 11.7 (K. YOUNG, WRIGHTWOOD, CA)
1750-32 V1178 SCO JUN 27.2631 11.8 (J. YOUNG, WRIGHTWOOD, CA)
1750-32 V1178 SCO JUN 27.2812 11.4 (J. BEDIENT, HONOLULU, HI)
1750-32 V1178 SCO JUN 27.4589 12.0: (P. NELSON, ELLINBANK,
AUSTRALIA)
1750-32 V1178 SCO JUN 28.1041 12.2: (E. VAN BALLEGOIJ,
ORANJESTAD, ARUBA)
1750-32 V1178 SCO JUN 30.2722 12.4 (R. ROYER, LAKEWOOD, CA)
1750-32 V1178 SCO JUL 01.4950 12.0: (P. NELSON, ELLINBANK,
AUSTRALIA)
1750-32 V1178 SCO JUL 04.4389 11.5 (P. NELSON, ELLINBANK,
AUSTRALIA)
1750-32 V1178 SCO JUL 05.2083 11.2 CCDV (R. ROYER, LAKEWOOD, CA)
1750-32 V1178 SCO JUL 08.2429 11.2 (R. ROYER, LAKEWOOD, CA)
1750-32 V1178 SCO JUL 09.2256 11.2 (R. ROYER, LAKEWOOD, CA)
1750-32 V1178 SCO JUL 10.25 11.4 (R. ROYER, LAKEWOOD, CA)
1750-32 V1178 SCO JUL 13.2672 12.2 CCDV (R. ROYER, LAKEWOOD, CA)
Please use the 'd' scale AAVSO chart
(http://www.aavso.org/alerts/alert285/alert285.stm)
to observe this novalike variable, and report your observations of 1750-32
V1178 SCO
to AAVSO Headquarters, making sure to indicate which comparison star(s) you
used.
For more information consult AAVSO Alert Notice #285 at the URL below:
http://www.aavso.org/alerts/alert285/alert285text.stm
Please watch for the forthcoming 'f' scale chart on our web site.
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4. COMMENTS ON LPV'S BY J.A.M.
Below is a list of some LPVs that may be of interest to you due
to their location, interesting behavior and/or because they are in
need of more observaitons at this time. We realize that some of these
stars may have charts with inadequate comparison star sequences that
need improvement. Please continue to use the existing charts - regardless
of how poor - until we have better established comparison stars
magnitudes which is an on-going project that we are working on.
1346-77 T Aps <9.1-14.7>
The cycle in 2000 had very few positive observations. Southern
hemisphere observers, we are depending on you to go for it at all
phases of the light curve.
1353-04 SY VIR <9.0-15.0>
Maxima in 2000 is about 1 magnitude fainter than average.
The minima are poorly observed. Use the e scale AAVSO preliminary
chart that has well measured faint comparison stars to observe it as
it is brightening to maximum.
1409-59 R Cen <5.8-11.1>
This easy-to-observe star is unique - it is one of only two Mira type
LPVs (the other is 1528-49 R Nor) which has double maxima. In recent
years its period and amplitude of variation has decreased. Studying
the longterm AAVSO data, we suggest that it is
undergoing a Helium-Shell Flash phase. See long abstract by G. Hawkins,
J. Mattei, and G. Foster in JAAVSO, 28, 56, (2000) and in PASP, 113,
501,(2001) and another recent article by W. S. G. Walker and
J. Greaves in JAAVSO, 29, 105; 2001.
1611-22B S Sco <10.5-14.6>
Needs more observations at all phases. Maxima in 2000 was
about a magnitude fainter than its average maximum
magnitude of 10.5. Observers with large telescopes may also want to go
after 1611-22A R Sco, which is just south of S Sco and fading to its
minimum, predicted for mid-September.
1613+26 NP Her (9.3 - 12.8)
Its recent two cycles in 1999 and 2000 have had very wide
(lasting 2.5 months) and faint maxima.
1623-19 Y Sco <11.3-15.0>
Another southern variable in need of observations at all
phases. We received very few observations for the 2000 cycle.
Use the c and d standard charts. The 48 comp. star to the north-west
will help you to locate it.
1626+23 DO Her 10.3-(16.0
The light curve has significant number of discordant observations
and scatter. The scatter may be due to some observers using a
non-AAVSO comparison star sequence. Please use the d and e scale
standard charts.
1839+22 AE Her 8.9-15.2
The maxima in October 2000 was very faint - at magnitude 11.2
Significant scatter exists around maximum. We have d and e preliminary
charts.
1853+16 EU Aql <11.4-15.1>
This star is in need of observations throughout its light curve,
particularly around minimum and as it brightens to maximum now.
Use e scale AAVSO standard chart even though it needs a better
comparison star sequence.
1906+43 ST Lyr <9.8-<15.5>
Needs more observations around minimum, now. For several years we have
had large gaps around minimum, making the predictions of
its minima very difficult.
1910-17 T Sgr (8.0 - 12.6)
The ascending branch of the recent cycle was much steeper,
i.e the rise to maximum faster, and the following maximum much wider
than usual. Needs more observations as it is slowly brightening from
its recent minimum in June. Will it again rise to maximum
faster than usual??
1934+28 BG Cyg <9.1-12.4>
This star has all the features of varying cycles - varying level
of maximum and minimum brightness, varying amplitude,
and "humps" on the ascending branch of the light curve. The
recent maximum in 2000 was faint and a very wide one - the star
was at mean magnitude 10.1 for almost 100 days, from July to October.
1939-72 T Pav (8.0 - 13.0)
Needs more observations at all phases. The recent maximum has large
scatter in the data. Please use the d scake standard chart.
2022-40 U Mic <8.8-14.0>
This star is in desperate need of observations at all phases.
Only few points exist in the database since 1999. Presently it is
fading to minimum (predicted for Aug 07).
2042-15 U Cap 11.1-14.8
Another LPV in desperate need of observations at all phases,
particularly at minimum; has a good e scale standard chart.
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5. COMMENTS BY MIKE SIMONSEN - on cataclysmic and other interesting
variables to watch for July and August, 2001.
Please note that this is not meant to be a comprehensive list of CVs to
observe in the next few months. This is only meant to point out a few
interesting stars, mostly CVs, to think about while planning your own
observing program.
1510+83 Z UMi - A circumpolar R CrB type star that began a
rapid decline in early March. Currently at minimum, near 16th
magnitude. When will it come back up?
1523+62 ES Dra - Rather ambiguous data in the database.
Its type is still uncertain. Is it NL or UG? Only time and more
observations will tell. Very good charts for this one are now available.
1544+28A R CrB - A star for everyone. Currently at maximum, but
could go into one of it's characteristic fades any time. Be careful
in identifying the comparisons to the east when swinging binoculars
around. R CrB was the Variable Star of the Month for January, 2000:
http://www.aavso.org/vstar/vsotm/0100.stm
1555+26 T CrB - A recurring nova that could suddenly brighten
at any moment... or not. Easily visible in smaller telescopes.
1621+39 V844 Her - This UGSU gets as bright as 12th magnitude when
in outburst. Lately, the typical outburst cycle seems to be about eleven
months. That would mean it's due any time now. Don't confuse it with
the 141 comparison close by.
1640+25 AH Her - A very active UGZ star that ranges from 14th
magnitude to 11th magnitude. When at minimum it can be a challenge
to estimate, due to its very close companion. When in outburst, suitable
comparisons are spread far and wide. Well worth the challenge though,
because it is always doing something!
1744-06 RS Oph - Another recurring nova. The last outburst was
in 1985. Maybe not overdue yet, but there was only a nine year calm
between the 1958 and 1967 eruptions. This one is easy to find in a
well populated field, and bright enough for smaller telescopes.
No excuses for missing it when it goes off. RS Oph was also
the Variable Star of the Month for May, 2000:
http://www.aavso.org/vstar/vsotm/0500.stm
1848+26 CY Lyr - Maybe it's not earth shattering news when
it goes into outburst because it does it so often. But, if you can
see down to the mid-thirteens with your scope and actually want
to *see* a CV in outburst in the next couple months, keep an eye on
this field. Located in a nice open cluster.
1916-28 V730 Sgr - This one is for our southern observers. There
is almost no data for this star in the AAVSO database. You can help
change that, and we now have excellent charts for this field.
2007+20 FG Sge - This "peculiar" central star of a planetary
nebula is often mistaken for it's close companion. Exhibits deep
irregular fades like an R CrB. Currently at or near minimum.
Should be on the way up soon. Will it recover or will it fade again
after coming half way up to maximum?
Ron Royer (RR) wrote a paper about FG Sge in JAAVSO, Vol. 27,
146, (1999) which can also be read in full through
ADS at the URL below (should be all on one line):
http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1999
JAVSO..27..146R&db_key=AST&high=39ad50824516343
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6. RECENTLY PUBLISHED CHARTS
New charts have recently been released for a group of CVs that had no
previous AAVSO charts.
DESIGNATION NAME RANGE TYPE SCALES
0748+63 HT Cam 17.2-18.6B XM/UG? b,d,f,br,dr,fr*, and CCD f
0845+03 CT Hya 14.2-18.5V UGSU b,d,f,br,dr,fr, and CCD f
0909-06 MM Hya 13.0-18.9V UGSU b,d,f,br,dr,fr, and CCD f
1326-29 LY Hya 14.0-18.5V UGSU b,d,f,br,dr,fr, and CCD f
1424-25 GY Hya 14-16p UG: b,d,f,br,dr,fr, and CCD f
1802+31 V1008 Her 13.5-19.3V UGSS b,d,f,br,dr,fr, and CCD f
1804+38 PR Her 14.0-21.0V UG b,d,g,br,dr,gr, and CCD g
1916-28 V730 Sgr 12.8-(17.5p UGSS: d,f,dr,fr
1920+52 V1113 Cyg 14.0-19.3V UGSU d,f,dr,fr
(* br,dr,fr -- "reversed" charts for telescopes with odd number of
reflections such as Schmidt-Cassegrain telescopes and refractors)
They can be found at /observing/charts/new061501.stm .
Watch the AAVSO web site for more charts of new CVs that will be
released later in the month.
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7. MIRA'S COMPANION
Mira has a hot, faint companion that was long known to be somewhere
between a white dwarf and a blue main-sequence star. Edward M. Sion and John
J. Bochanski (Villanova University) determined that it is a relatively cool
white dwarf surrounded by a hotter accretion disk of gas that is being
collected from Mira's out flowing stellar wind.
For more information please check;
SKY&TEL(news) http://www.skypub.com/news/010608.html
AAS (Abstracts- Pasadena, CA June 2001 )
http://www.aas.org/publications/baas/v33n2/aas198/517.htm
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EYEPIECE Views is published bimonthly and when circumstances warrant
via e-mail. An archive is available at http://www.aavso.org/eyepieceviews/ .
Please send comments and suggestions to gamze@aavso.org.
To receive EYEPIECE Views via e-mail send a message to
majordomo@aavso.org with "subscribe eyepieceviews" in the body of the
e-mail. To unsubscribe, place "unsubscribe eyepieceviews" in the e-mail.
The AAVSO has many free online publications including "CCD
Views", a similar newsletter intended for CCD observers. To learn
more and subscribe visit: http://www.aavso.org/mailinglists.stm
Good observing!
Gamze Menali,AAVSO Technical Assistant (MGQ)
Aaron Price, AAVSO Technical Assistant (PAH)
Mike Simonsen, AAVSO Observer (SXN)
Copyright 2001, American Association of Variable Star Observers
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THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
Tel. 617-354-0484 Fax 617-354-0665
http://www.aavso.org
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