Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A deep UVBRI CCD photometric study of open clusters Tr 1 and Be 11   We present deep $UBVRI$ CCD photometry for the young open star clusters Tr 1
and Be 11. The CCD data for Be 11 is obtained for the first time. The sample
consists of $\sim$ 1500 stars reaching down to $V$ $\sim$ 21 mag. Analysis of
the radial distribution of stellar surface density indicates that radius values
for Tr 1 and Be 11 are 2.3 and 1.5 pc respectively. The interstellar extinction
across the face of the imaged clusters region seems to be non-uniform with a
mean value of $E(B-V)$ = 0.60$\pm$0.05 and 0.95$\pm$0.05 mag for Tr 1 and Be 11
respectively. A random positional variation of $E(B-V)$ is present in both the
clusters. In the cluster Be 11, the reason of random positional variation may
be apparent association of the HII region (S 213). The 2MASS $JHK$ data in
combination with the optical data in the cluster Be 11 yields $E(J-K)$ =
0.40$\pm$0.20 mag and $E(V-K)$ = 2.20$\pm$0.20 mag. Colour excess diagrams
indicate a normal interstellar extinction law in the direction of cluster Be
11. The distances of Tr 1 and Be 11 are estimated as 2.6$\pm$0.10 and
2.2$\pm$0.10 Kpc respectively, while the theoretical stellar evolutionary
isochrones fitted to the bright cluster members indicate that the cluster Tr 1
and Be 11 are 40$\pm$10 and 110$\pm$10 Myr old. The mass functions corrected
for both field star contamination and data incompleteness are derived for both
the clusters. The slopes $1.50\pm0.40$ and $1.22\pm0.24$ for Tr 1 and Be 11
respectively are in agreement with the Salpeter's value. Observed mass
segregations in both clusters may be due to the result of dynamical evolutions
or imprint of star formation processes or both.

19
The categories of this paper are: eess
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th