MISAO Project

Home Page       Updated on July 13, 2002

    MisV Stars in the TASS Tenxcat Database    

May 14, 2000
Yoshida, S.; Richmond, M.

1. Initial Research by Seiichi Yoshida

There are many photometric data of stars between Decl. +1.5 deg and -2.4 deg in the TASS tenxcat database, which are available at the TASS web pages. Some of MisV stars, the new variable stars discovered in the MISAO Project, locate in this area. So I searched the TASS database for the data of those MisV stars.

Here is the list of MisV stars in this area.

CodeR.A. (J2000.0) Decl.MaxMin
MisV000918 59 11.39-01 34 10.911.5C13.4C
MisV011418 59 06.54-00 00 44.613.8C[14.8C
MisV013019 02 25.63-00 30 14.510.8C12.0C
MisV013618 59 29.49-00 41 55.112.9C14.5C
MisV013819 01 20.23-01 24 12.112.2C13.3C
MisV014219 00 49.48-01 53 40.812.1C13.3C
MisV014319 00 17.64-02 02 36.612.3C13.4C
MisV014419 00 29.32-01 54 50.812.2C13.8C
MisV016118 59 11.08-01 38 50.113.2C[14.6C
MisV016219 02 42.87-01 42 50.812.7C14.5C
MisV016419 02 15.88-00 33 17.811.8C14.0C
MisV016519 02 36.50-00 47 39.612.8C13.8C
MisV025018 57 51.03-01 59 00.810.7C11.6C
MisV033918 58 39.54-00 54 17.713.4C14.7C
MisV035119 00 53.82+00 06 24.012.5C14.3C
MisV035219 02 04.41+00 15 42.713.0C14.6C
MisV042918 42 31.88-01 46 31.212.8C13.7C
MisV043018 43 39.03-00 04 29.213.0C13.9C
MisV046816 57 29.81+00 00 01.012.5C13.5C
MisV057318 02 08.02-02 22 30.714.6C16.9C
MisV069619 02 36.04-01 06 17.012.6C14.2C
MisV069719 00 42.17-01 08 13.113.3C[14.7C
MisV069819 02 28.42-01 12 16.613.7C16.0C
MisV069919 00 19.08-00 59 56.213.8C15.8C
MisV070018 57 24.95-01 33 15.712.9C15.3C
MisV070119 00 31.77-02 12 20.413.0C14.8C
MisV074017 59 41.66-00 35 31.012.9C14.7C
MisV082417 57 11.76-00 28 45.013.3C14.1C

Then I searched the TASS database for these 28 stars. I tried to find the data within 0.02 deg = 1.2 arcmin from the position of each MisV star. As a result, the data of 9 stars are found.

The maximum brightness in the MISAO database of those 9 stars are:

10.7, 11.5, 12.1, 12.2, 12.9, 12.9, 13.0, 13.3, 13.4

On the other hand, the maximum brightness in the MISAO database of the rest are:

10.8, 11.8, 12.2, 12.3, 12.5, 12.5, 12.6, 12.7, 12.8, 12.8, 12.9, 13.0, 13.0, 13.2, 13.3, 13.7, 13.8, 13.8, 14.6

I do not know why very bright stars like MisV0130 (10.8 mag at maximum) or MisV0164 (11.8 mag at maximum) were not observed by TASS.

Here are the comments on those 9 stars.

* MisV0009 = TASS J185911.0-013413

The light curve is very strange. The TASS I-band observations show both the slow fading and short-time eclipse-like fading. The elicpse-like event occurred between 2450995 and 2451022 (JD), with a large amplitude as maximum 10.2 mag and minimum 12.4 mag.

The MISAO observations show the brightening. If it is linked to the slow fading observed by TASS I-band, the period is 500 days or more, and it was at minimum around 2451100. But while TASS I-band observations were detecting the slow fading, TASS V-band observations show it was constant, or maybe slightly brightening.

* MisV0136 =? TASS 5115-00315

The TASS observations show it is constant. Probably, the TASS observed the nearby star, just southwest of MisV0136. If not, it began to fade out at around 2451100 (JD) after the TASS observations finished, and kept fading for 300 days.

* MisV0142 = TASS 5132-00240 = TASS J190049.2-015331

The variability of TASS I-band and V-band are well corresponding, showing the long period variability. It seems to be linked with the MISAO observations. It will be a SR-type variable star with a small amplitude of about 1.3 mag and a period of 400-500 days.

* MisV0144 = TASS 5132-00144

The light curve is strange. The TASS V-band observations keep constant, but it was faint sometimes. The TASS I-band observations maybe show the short period variability between 10.5 and 11.5 mag with a rough period of 20-30 days. There are only few MISAO observations.

* MisV0250 = TASS J185751.3-015857

The total light curve containing the TASS and MISAO observations shows the long period variability with a period of about 400 days.

* MisV0339 =? TASS J185837.2-005406

The TASS observations show it is constant. Probably, the TASS observed the nearby star, just southeast of MisV0339.

* MisV0701 = TASS J190030.4-021208 = TASS J190031.2-021212

The total light curve containing the TASS and MISAO observations implies that it is a SR-type with a period of about 300 days. In that case, it must have been at minimum around 2451200 (JD), after the TASS observations and before the MISAO observatinos. But if it keeps fading since 2451050 (JD), the period will be much longer.

* MisV0740 = TASS J175944.0-003554

Both the TASS observations and the MISAO observations are detecting the fading for about 100 days. So the period is uncertain. But it will be a long period variable star.

* MisV0824 = TASS J175712.0-002846

The TASS observations for 100 days show it was at maximum. The MISAO observations for 300 days show it was at minimum. Therefore, it is a long period variable star with a half period of 450 days from maximum to minimum.

2. Further Research by Michael Richmond

Yoshida-san mentions some matches between variable stars seen by MISAO and seen by TASS. He found matches in 9 out of 28 cases, and wondered why 19 of the stars weren't found in the TASS database. Let me explain, star by star.

In some cases, the stars were seen by TASS cameras, but fewer than 10 times. Only stars observed at least 11 times were placed into the "tenxcat" catalogue, which is available for public viewing and searching.

MisV0114 very faint, few observations of this field by TASS, star located near edge of the field
MisV0130 measured 9 times by TASS, so not put into the "tenxcat" catalog. All measurements in I-band.
MisV0138 measured 6 times by TASS in I-band
MisV0143 possible match, 14 arcsec difference, with a star measured 3 times in I-band by TASS
MisV0144 measured 10 times by TASS in I-band
MisV0161 possible match 12 arcsec away measured 6 times in I-band
MisV0162 possible match 14 arcsec away measured 8 times in I-band
MisV0164 measured 7 times in I-band, 1 time in V-band
MisV0165 measured 2 times in I-band
MisV0339 possible match 16 arcsec away measured 4 times in V-band
MisV0351 measured 5 times in I-band
MisV0352 possible match 11 arcsec away measured 4 times in I-band
MisV0429 no match at all, even though field was covered many times by TASS. Strange?
MisV0430 measured 8 times in I-band
MisV0468 no match at all
MisV0573 measured 9 times in I-band
MisV0696 measured 8 times in I-band
MisV0697 no match, even though field covered plenty of times
MisV0698 no match, even though field covered plenty of times (star probably too faint at minimum)
MisV0699 no match, even though field covered plenty of times (star probably too faint at minimum)
MisV0700 possible match 13 arcsec away measured 1 time in V-band
MisV0701 this appears in the TASS "tenxcat" catalog as two close stars, which are probably really the same star. They are TASS 190030.4-021208 (16 I-band) and TASS 190031.2-021212 (12 I-band).
MisV0740 no match

All measurements here are "raw" magnitudes. They have not been corrected to place them on the standard Johnson-Cousins scale. V-band should be close to the standard, but I-band may be different.

The numbers labelled "tass_id" are internal ID numbers in the complete TASS database; they do not correspond to the numbers in the public "tenxcat" catalog.

MisV0130 = tass_id 12050621

            Julian Date|I-band
-----------------------+------
         2450938.863679| 9.806
          2450928.89104| 9.794
         2450928.893379| 9.912
           2450952.8297| 9.933
         2450951.829239| 9.894
          2451022.63779|  9.85
         2450995.714019|10.095
          2450640.68746| 9.938
          2451027.62611| 9.918

MisV0138 = 12198734

            Julian Date|I-band
-----------------------+------
         2450961.800679|10.248
         2450995.713279|10.328
          2450967.79057|10.426
          2450951.82849| 10.41
          2450952.82896| 10.25
         2451022.637039|10.662

MisV0143 = tass_id 12614671 ??

            Julian Date|I-band
-----------------------+------
         2450995.712569|12.265
         2450696.618429| 12.03
           2450717.5613|12.046

MisV0144 = tass_id 11948558

            Julian Date|I-band
-----------------------+------
          2451027.62478|10.552
         2450927.896509|10.241
          2450939.86353|  10.2
         2450951.827909|10.217
         2450952.828389|10.123
         2450928.891979|10.166
         2450995.712689|10.235
         2450967.789979|10.081
          2451006.76303|12.527
         2451022.636469|10.463

MisV0161 = tass_id 11948325 ?

            Julian Date|I-band
-----------------------+------
          2450967.78908|12.077
          2450952.82749|11.335
         2450939.862639|11.534
         2450928.891079|11.006
          2450927.89563|11.247
            2450951.827|11.846

MisV0162 = tass_id 11948958 ?

            Julian Date|I-band
-----------------------+------
         2450927.898039|11.151
         2450952.829909|10.976
           2450928.8936|10.938
          2450939.86506|11.012
          2450951.82944|10.962
         2450995.714219|11.832
         2450967.791569| 11.33
          2450640.68764|12.122

MisV0164 = tass_id 1719130

            Julian Date|I-band
-----------------------+------
         2450938.863559|10.181
          2450928.89092|10.101
         2450995.713899|11.427
         2450952.829599|10.495
         2450928.893269|10.234
         2450951.829129|10.375
          2451022.63768|12.037

            Julian Date|V-band
-----------------------+------
         2451038.634109|13.504

MisV0165 = tass_id 12473748

            Julian Date|I-band
-----------------------+------
         2450967.791499|11.665
          2450640.68758|11.721

MisV0339 = tass_id 12614376 ??

  
            Julian Date|V-band
-----------------------+------
         2450995.752539|13.996
         2451037.633599|13.164
         2451038.631599|13.834
          2451046.60978|13.653

MisV0351 = tass_id 12050452

            Julian Date|I-band
-----------------------+------
         2450961.800379|10.389
         2450938.862639|10.296
          2450928.88999|10.153
         2450928.892219|10.311
         2450952.828639|10.461

MisV0352 = tass_id 12266763 ??

            Julian Date|I-band
-----------------------+------
          2450961.80119|11.284
         2450938.863429|12.287
          2450928.89079|12.065
          2450952.82945|11.745

MisV0430 = tass_id 12048344

            Julian Date|I-band
-----------------------+------
         2450961.870819|11.745
          2450938.85073|11.619
         2450928.877909|12.477
          2450915.91361|11.436
          2450914.91637|11.206
          2450995.70096|12.688
          2450952.81673|12.025
         2450928.880309|  11.6

MisV0573 = tass_id 11935454

            Julian Date|I-band
-----------------------+------
         2450927.856019|12.513
         2450939.823049|12.251
          2450951.78751|12.187
            2450952.788|12.322
          2450955.77882|12.333
          2451006.63891| 12.87
          2450967.74958|12.785
          2450995.67224| 12.86
         2450640.645649|13.739

MisV0696 = tass_id 1721440

            Julian Date|I-band
-----------------------+------
         2450938.863789| 9.286
         2450928.891139| 9.101
         2450967.791499| 9.645
          2450640.68758| 9.572
          2450995.71413| 9.824
          2450952.82983| 9.127
         2450928.893509| 9.169
         2450951.829359| 9.382

MisV0700 = tass_id 1686152 ?

            Julian Date|V-band
-----------------------+------
         2451056.582779|14.023

MisV0701 = tass_id 12817002 and 11948564 ?

            Julian Date|I-band    this is 11948564
-----------------------+------
          2451083.55254|11.624
         2451047.650489|11.714
             2450967.79|11.851
         2450640.686139|13.229
         2450995.796339|12.687
          2450995.71272|11.529
         2450928.891999|12.117
         2450939.863539|12.086
         2450927.896519|12.772
          2450952.82841|12.136
          2450951.82792|12.389
         2451006.762999|11.946

            Julian Date|I-band    this is 12817002 
-----------------------+------
         2451053.635439|11.464
          2451055.62971|11.221
          2451048.64887|10.996
         2451056.627489|11.944
         2450696.618569|12.195
         2451027.624799|11.292
          2451027.70843|11.454
          2451045.65552|11.771
          2451068.59253|11.615
          2451066.59769|11.186
         2450717.561429|12.499
         2451070.586769|11.494
          2451069.58966|11.651
          2451007.76138|12.513
         2451026.711589| 11.32
         2451022.636489|11.073

Copyright(C) MISAO Project (comet@aerith.net). All rights reserved.