Exception in thread "main" java.lang.IllegalArgumentException: Unknown entity: br.com.alura.modelo.Conta

package br.com.alura.modelo;

import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

import org.hibernate.annotations.Entity;

@Entity
public class Conta {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Integer id;
    private String titular;
    private String numero;
    private String banco;
    private String agencia;




    public Integer getId() {
        return id;
    }


    public void setId(Integer id) {
        this.id =id;
    }


    public String getTitular() {

        return titular;
    }

    public void setTitular(String titular) {

        this.titular = titular;
    }


    public String getNumero() {
        return numero;
    }


    public void setNumero(String numero) {

        this.numero = numero;
    }


    public String getBanco() {

        return banco;
    }

    public void setBanco(String banco) {

        this.banco = banco;
    }

    public String getAgencia () {

        return agencia;
    }


    public void setAgencia (String agencia) {

        this.agencia = agencia;
    }


}

              <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>

                 <class>br.com.alura.modelo.Conta</class>                     

                 <!--Propriedade do JDBC   -->

                 <properties>

                         <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
                         <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost/financas" />    

                         <property name="javax.persistence.jdbc.user" value="root" />
                                     <property name="javax.persistence.jdbc.password" value="123456" />


                     <!-- Configurações específicas do Hibernate -->

                         <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect" />

                         <property name="hibernate.hbm2ddl.auto" value="update" />
                         <property name="hibernate.show_sql" value="true" />
                         <property name="hibernate.format_sql" value="true" />



                 </properties>

Ja quebrei a cabeça e continua exibindo o erro.

INFO: HHH000490: Using JtaPlatform implementation: [org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform] Exception in thread "main" java.lang.IllegalArgumentException: Unknown entity: br.com.alura.modelo.Conta at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:808) at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:789) at br.com.alura.principal.TesteInserir.main(TesteInserir.java:25)