TO KNOW THE STARRY HEAVENS 
81 
stars do. By the time this is read it 
will probably he invisible to the naked 
eye. 
About forty such stars have been ob- 
served and recorded. In earlier times 
only the bright ones were seen. Now, 
when the sky is photographed, fainter 
ones are found. Most of the recent 
discoveries have been found upon ex- 
amination of photographs of the same 
region taken at different times. In this 
way the star may have disappeared be- 
nitude of the new star which appeared 
in Perseus in lyoi, while it was visible 
to the naked eye. It shows the sudden 
rise to a maximum brightness and the 
gradual decline in brightness, with oc- 
casional flare-ups. Other novae act 
similarly. 
Work for Amateur Telescopists. 
It is with much pleasure that we call 
attention to The American Association 
of Variable Star Observers that has 
Figure 4. Light curve of Nova Persei which appeared in 1901. 
fore its existence was discovered. It 
can be seen that the appearance of a 
new star, or at least their detection, has 
not been a common event. The ap- 
pearance of one as bright as this is 
quite rare. It is true a brighter one 
appeared in Aquila as recently as 1918, 
but that one was brighter than any 
since 1604. 
Temporary stars rise from obscurity 
to conspicuousness in a very brief in- 
terval and then fade out much more 
slowly. There are frequently flashes of 
increased brightness as it fades in gen- 
eral. There is no undisputed case of a 
star long known which has disappeared 
nor of one which appeared and re- 
mained permanently visible. We do 
not know what causes these outbursts. 
It has been suggested that they are 
caused by some sort of a collision. This 
may be true, but there are objections to 
this explanation. We do not see the 
outburst until long after it has occurred. 
If the distance of the star is one hun- 
dred light years then the outburst oc- 
curred one hundred years ago. The 
distance is more likely to be much 
greater than this. 
Figure 4 shows variations in the mag- 
been so well developed by the Secre- 
tary, William T. Olcott, 62 Church 
Street, Norwich, Connecticut. We ad- 
vise every one who has a telescope and 
can spare the time to get busy at once 
in this enjoyable work, and every one 
who is interested in astronomy but has 
no telescope to obtain at least a small 
instrument at the earliest possi- 
ble. The Association is growing 
rapidly. Last year forty new mem- 
bers were elected and thirty more have 
joined the ranks since May. the total 
membership now being two hundred 
and four. Everybody who knows any- 
thing about astronomy knows that the 
study of variable stars is enjoyable and 
opens to the amateur a splendid field 
for useful work. 
A Picture. 
Beyond the gold of ripened grain, 
The blue of distant hills, 
O’er the rim of which the setting sun 
The world with glory fills. 
The low, round hills are crowned with 
gold, 
The gold of ungarnered grain; 
Rare beauty erst their summer dower, 
Now wealth comes in its tra'n. 
- — Emma Pe rce. 
